SELECT 
  company_descriptions.*, 
  companies.*, 
  vendor_plan_descriptions.plan, 
  seo_names.name as seo_name, 
  seo_names.path as seo_path, 
  vendor_ga_tracking_code, 
  vendor_fb_tracking_code, 
  AVG(discussion_rating.rating_value) AS average_rating, 
  CONCAT(
    companies.company_id, 
    '_', 
    IF (
      discussion_rating.thread_id, discussion_rating.thread_id, 
      '0'
    )
  ) AS company_thread_ids 
FROM 
  companies AS companies 
  LEFT JOIN company_descriptions AS company_descriptions ON company_descriptions.company_id = companies.company_id 
  AND company_descriptions.lang_code = 'en' 
  LEFT JOIN vendor_plan_descriptions ON companies.plan_id = vendor_plan_descriptions.plan_id 
  AND vendor_plan_descriptions.lang_code = 'en' 
  LEFT JOIN seo_names ON seo_names.object_id = 4439 
  AND seo_names.type = 'm' 
  AND seo_names.dispatch = '' 
  AND seo_names.lang_code = 'en' 
  LEFT JOIN discussion as discussionA ON discussionA.object_id = companies.company_id 
  AND discussionA.object_type = 'M' 
  LEFT JOIN discussion_posts ON discussion_posts.thread_id = discussionA.thread_id 
  AND discussion_posts.status = 'A' 
  LEFT JOIN discussion_rating ON discussionA.thread_id = discussion_rating.thread_id 
  AND discussion_rating.post_id = discussion_posts.post_id 
WHERE 
  companies.company_id = 4439

Query time 0.00100

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "2.55"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "companies",
          "access_type": "const",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "company_id"
          ],
          "key_length": "4",
          "ref": [
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.00",
            "eval_cost": "0.10",
            "prefix_cost": "0.00",
            "data_read_per_join": "14K"
          },
          "used_columns": [
            "company_id",
            "status",
            "company",
            "lang_code",
            "address",
            "city",
            "state",
            "country",
            "zipcode",
            "email",
            "phone",
            "url",
            "storefront",
            "secure_storefront",
            "entry_page",
            "redirect_customer",
            "countries_list",
            "timestamp",
            "shippings",
            "logos",
            "request_user_id",
            "request_account_name",
            "request_account_data",
            "plan_id",
            "stripe_connect_account_id",
            "identifier_facebook_pixel",
            "featured_products",
            "sd_ga_tracking_code",
            "paypal_commerce_platform_account_id",
            "tagline",
            "url_facebook",
            "url_instagram",
            "url_twitter",
            "url_pinterest",
            "announcement",
            "shippo_api_token",
            "shippo_carrier",
            "shippo_service_type",
            "vendor_ga_tracking_code",
            "vendor_fb_tracking_code",
            "custom_domain",
            "custom_domain_status",
            "taxjar_key",
            "taxjar_export_statuses",
            "taxjar_export_csv_data",
            "ag_hide_city",
            "updated_timestamp",
            "suspend_date",
            "grace_period_start",
            "last_time_suspended",
            "last_debt_notification_time",
            "tax_number",
            "stripe_connect_account_type",
            "registered_from_storefront_id"
          ]
        }
      },
      {
        "table": {
          "table_name": "company_descriptions",
          "access_type": "const",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "company_id",
            "lang_code"
          ],
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            "const",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.00",
            "eval_cost": "0.10",
            "prefix_cost": "0.00",
            "data_read_per_join": "1K"
          },
          "used_columns": [
            "company_id",
            "lang_code",
            "company_description",
            "terms",
            "subdomain_colors",
            "i18n_company",
            "i18n_address",
            "i18n_city"
          ]
        }
      },
      {
        "table": {
          "table_name": "vendor_plan_descriptions",
          "access_type": "const",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "plan_id",
            "lang_code"
          ],
          "key_length": "10",
          "ref": [
            "const",
            "const"
          ],
          "rows_examined_per_scan": 1,
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          "cost_info": {
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            "prefix_cost": "0.00",
            "data_read_per_join": "1K"
          },
          "used_columns": [
            "plan_id",
            "lang_code",
            "plan"
          ]
        }
      },
      {
        "table": {
          "table_name": "seo_names",
          "access_type": "ref",
          "possible_keys": [
            "PRIMARY",
            "dispatch"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "object_id",
            "type",
            "dispatch",
            "lang_code"
          ],
          "key_length": "206",
          "ref": [
            "const",
            "const",
            "const",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.74",
            "eval_cost": "0.10",
            "prefix_cost": "0.84",
            "data_read_per_join": "1K"
          },
          "used_columns": [
            "name",
            "object_id",
            "type",
            "dispatch",
            "path",
            "lang_code"
          ]
        }
      },
      {
        "table": {
          "table_name": "discussionA",
          "access_type": "const",
          "possible_keys": [
            "object_id"
          ],
          "key": "object_id",
          "used_key_parts": [
            "object_id",
            "object_type"
          ],
          "key_length": "6",
          "ref": [
            "const",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "using_index": true,
          "cost_info": {
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            "prefix_cost": "1.51",
            "data_read_per_join": "24"
          },
          "used_columns": [
            "thread_id",
            "object_id",
            "object_type"
          ]
        }
      },
      {
        "table": {
          "table_name": "discussion_posts",
          "access_type": "ref",
          "possible_keys": [
            "thread_id",
            "thread_id_2"
          ],
          "key": "thread_id_2",
          "used_key_parts": [
            "thread_id",
            "status"
          ],
          "key_length": "6",
          "ref": [
            "goimagine.discussionA.thread_id",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "using_index": true,
          "cost_info": {
            "read_cost": "0.25",
            "eval_cost": "0.18",
            "prefix_cost": "1.94",
            "data_read_per_join": "787"
          },
          "used_columns": [
            "post_id",
            "thread_id",
            "status"
          ]
        }
      },
      {
        "table": {
          "table_name": "discussion_rating",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY",
            "thread_id"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "post_id"
          ],
          "key_length": "3",
          "ref": [
            "goimagine.discussion_posts.post_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
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            "eval_cost": "0.18",
            "prefix_cost": "2.56",
            "data_read_per_join": "28"
          },
          "used_columns": [
            "rating_value",
            "post_id",
            "thread_id"
          ],
          "attached_condition": "<if>(is_not_null_compl(discussion_rating), (`goimagine`.`discussion_rating`.`thread_id` = `goimagine`.`discussionA`.`thread_id`), true)"
        }
      }
    ]
  }
}

Result

company_id lang_code company_description terms subdomain_colors i18n_company i18n_address i18n_city status company address city state country zipcode email phone url storefront secure_storefront entry_page redirect_customer countries_list timestamp shippings logos request_user_id request_account_name request_account_data plan_id stripe_connect_account_id identifier_facebook_pixel featured_products sd_ga_tracking_code paypal_commerce_platform_account_id tagline url_facebook url_instagram url_twitter url_pinterest announcement shippo_api_token shippo_carrier shippo_service_type vendor_ga_tracking_code vendor_fb_tracking_code custom_domain custom_domain_status taxjar_key taxjar_export_statuses taxjar_export_csv_data ag_hide_city updated_timestamp suspend_date grace_period_start last_time_suspended last_debt_notification_time tax_number stripe_connect_account_type registered_from_storefront_id plan seo_name seo_path average_rating company_thread_ids
4439 en <p>I embraced life as a full-time artist a few years ago, and I feel extremely grateful to be able to live with my creativity leading the way. Even though my art is always changing and evolving, the one constant is the source of inspiration. My inspiration is the natural world, and my hope is to help others feel a stronger connection to nature. Combining my experience as a former wildlife biologist with my passion for different mediums, please enjoy these heart-infused offerings. Currently my creative focus is dried flower arrangements. I grow and dry most of my own flowers, my garden being my happy place. Custom orders are accepted. My art is how I make my living, and words cannot express my appreciation for your purchase. However, I will try. Thank you!&nbsp;&nbsp;</p> {"tmenu_style":"V","default_colors":"N","link_color":"#007d89","label_color":"#00a0af","icon_color":"#00a0af","main_btn_color":"#6dd1d6","branded_text_color":"#00a0af","vbp_1_url":"","vbp_2_url":"","vbp_3_url":"","vba_1_url":"","vba_2_url":"","vba_3_url":""} Goosehill Gifts 6925 Riva Ridge Dr. SE TURNER A Goosehill Gifts 6925 Riva Ridge Dr. SE TURNER OR US 97392 goosehillgifts@gmail.com none Y 1637777585 0 1 acct_1Jzy9NFFsVHB4krb 155235,181257,181246,155251,155233,181254 Unique Gifts of Nature Inspired Home Decor! https://www.facebook.com/uniquegiftshop https://www.instagram.com/goosehillgifts/ <p>Hello!&nbsp;My inspiration is the natural world, and my hope is to help people feel a stronger connection to nature with unique and handmade pieces of home decor and more. My art is how I make my living. Words cannot express my appreciation for your purchase, but I will try. Thank you!</p> A N 0 0 0 0 0 S Starter Plan goosehill-gifts 5.0000 4439_1024437