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 = 7704 
  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 = 7704

Query time 0.00202

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "2.78"
    },
    "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"
          ],
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          "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": [
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            "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": "0.85",
            "eval_cost": "0.10",
            "prefix_cost": "0.95",
            "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": "1.74",
            "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": "2.16",
            "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": "2.78",
            "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
7704 en <p><span class="mt-xs-1" data-inplace-editable-text="story" data-endpoint="AboutPost" data-key="story" data-placeholder="How did you get started? What inspires you? We know each seller’s story is unique&mdash;tell yours here.">I started my photography journey as a way to spend time with my mom, who is a photographer. I loved learning the craft and the connection I feel with the wildlife. Friends and family have encouraged me to sell my prints as I get better, so I decided to give it a go. Recently, I started quilting. I have created some camera strap designs that incorporate my love of quilting with my love of photography. I also feature Calming Critters, designed by Paige. Paige designs and hand sews each critter for her customers to be the softest, cutest, most cuddly critters! They can be weighted, scented, and come in several sizes!</span> </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":""} MoosePaw Designs 209 South Balsam St Lakewood A MoosePaw Designs 209 South Balsam St Lakewood CO US 80226 moosepawdesigns@gmail.com +17202902022 none Y 1665085176 0 1 acct_1Lq5fJD1JzXMWphM 259194,259195,254503,254657,254682,260941,254888,254889 58UBTZGV8UFU4 Photography, Camera Straps, Calming Critters and More! https://www.facebook.com/profile.php?id=100085105492953 https://www.instagram.com/moosepawdesigns/ UA-244676043-2 A N 0 0 0 0 0 S Starter Plan moosepawdesigns 7704_0