SELECT 
  * 
FROM 
  companies AS com 
  LEFT JOIN products AS prod ON com.company_id = prod.company_id 
WHERE 
  prod.product_id = 82171

Query time 0.00073

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "1.00"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "prod",
          "access_type": "const",
          "possible_keys": [
            "PRIMARY",
            "idx_company_id"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "product_id"
          ],
          "key_length": "3",
          "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": "4K"
          },
          "used_columns": [
            "product_id",
            "product_code",
            "product_type",
            "status",
            "company_id",
            "list_price",
            "amount",
            "weight",
            "length",
            "width",
            "height",
            "shipping_freight",
            "low_avail_limit",
            "timestamp",
            "updated_timestamp",
            "usergroup_ids",
            "is_edp",
            "edp_shipping",
            "unlimited_download",
            "tracking",
            "free_shipping",
            "zero_price_action",
            "is_pbp",
            "is_op",
            "is_oper",
            "is_returnable",
            "return_period",
            "avail_since",
            "out_of_stock_actions",
            "localization",
            "min_qty",
            "max_qty",
            "qty_step",
            "list_qty_count",
            "tax_ids",
            "age_verification",
            "age_limit",
            "options_type",
            "exceptions_type",
            "details_layout",
            "shipping_params",
            "weight_lbs",
            "weight_oz",
            "product_tax_code",
            "deleted_at",
            "archived_at",
            "position"
          ]
        }
      },
      {
        "table": {
          "table_name": "com",
          "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"
          ]
        }
      }
    ]
  }
}