SELECT 
  cscart_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      cscart_products_categories.link_type = "M", 
      CONCAT(
        cscart_products_categories.category_id, 
        "M"
      ), 
      cscart_products_categories.category_id
    )
  ) AS category_ids, 
  product_position_source.position AS position 
FROM 
  cscart_products_categories 
  INNER JOIN cscart_categories ON cscart_categories.category_id = cscart_products_categories.category_id 
  AND cscart_categories.storefront_id IN (0, 1) 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  LEFT JOIN cscart_products_categories AS product_position_source ON cscart_products_categories.product_id = product_position_source.product_id 
  AND product_position_source.category_id = 7148 
WHERE 
  cscart_products_categories.product_id IN (
    85982, 85983, 85984, 85985, 85986, 85987, 
    85988, 85989, 85990, 85991, 85992, 
    85993, 85994, 85995, 85996, 85997, 
    85998, 85999, 86003, 86004, 86005, 
    86006, 86007, 86008, 86009, 86010, 
    86011, 86012, 86014, 86015, 86017, 
    86018, 86019, 86020, 86021, 86022, 
    86023, 86024, 86025, 86026, 86027, 
    86028, 86029, 86030, 86031, 86032, 
    86033, 86034
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00236

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "82.03"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "link_type",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 144,
            "rows_produced_per_join": 144,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "14.71",
              "eval_cost": "14.40",
              "prefix_cost": "29.11",
              "data_read_per_join": "2K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (85982,85983,85984,85985,85986,85987,85988,85989,85990,85991,85992,85993,85994,85995,85996,85997,85998,85999,86003,86004,86005,86006,86007,86008,86009,86010,86011,86012,86014,86015,86017,86018,86019,86020,86021,86022,86023,86024,86025,86026,86027,86028,86029,86030,86031,86032,86033,86034))"
          }
        },
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "nuie_scalesta_net.cscart_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 7,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "36.00",
              "eval_cost": "0.72",
              "prefix_cost": "79.51",
              "data_read_per_join": "18K"
            },
            "used_columns": [
              "category_id",
              "usergroup_ids",
              "status",
              "storefront_id"
            ],
            "attached_condition": "((`nuie_scalesta_net`.`cscart_categories`.`storefront_id` in (0,1)) and ((`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids` = '') or (0 <> find_in_set(0,`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids`)) or (0 <> find_in_set(1,`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids`))) and (`nuie_scalesta_net`.`cscart_categories`.`status` in ('A','H')))"
          }
        },
        {
          "table": {
            "table_name": "product_position_source",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id",
              "product_id"
            ],
            "key_length": "6",
            "ref": [
              "const",
              "nuie_scalesta_net.cscart_products_categories.product_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 7,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.80",
              "eval_cost": "0.72",
              "prefix_cost": "82.03",
              "data_read_per_join": "115"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}