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 = 7185 
WHERE 
  cscart_products_categories.product_id IN (
    85654, 84105, 83099, 92839, 92897, 92898, 
    92900, 92903, 92904, 92907, 92908, 
    92911, 92912, 92935, 92937, 92939, 
    92941, 92943, 92945, 93054, 93055, 
    93056, 93057, 93058, 93059, 93060, 
    93061, 93070, 93281, 93524, 93526, 
    93528, 93782, 93784, 93786, 94027, 
    94029, 94031, 94033, 94075, 94717, 
    94720, 94721, 94724, 94725, 94726, 
    94729, 94730, 94733, 94734, 94737, 
    94738, 94741, 94742, 94745, 94746, 
    94749, 96304, 96308, 96310, 96311, 
    96313, 96314, 96316, 96318, 96319, 
    96321, 96323, 96325, 96327, 96329, 
    96331, 96333, 96337, 97015, 97017, 
    97024, 97027, 97028, 97029, 97031, 
    97033, 97040, 97046, 97841, 97844, 
    97845, 97848, 97849, 97850, 97853, 
    97854, 97857, 97858, 97861, 97862
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00102

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "54.77"
    },
    "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": 96,
            "rows_produced_per_join": 96,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "9.89",
              "eval_cost": "9.60",
              "prefix_cost": "19.49",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (85654,84105,83099,92839,92897,92898,92900,92903,92904,92907,92908,92911,92912,92935,92937,92939,92941,92943,92945,93054,93055,93056,93057,93058,93059,93060,93061,93070,93281,93524,93526,93528,93782,93784,93786,94027,94029,94031,94033,94075,94717,94720,94721,94724,94725,94726,94729,94730,94733,94734,94737,94738,94741,94742,94745,94746,94749,96304,96308,96310,96311,96313,96314,96316,96318,96319,96321,96323,96325,96327,96329,96331,96333,96337,97015,97017,97024,97027,97028,97029,97031,97033,97040,97046,97841,97844,97845,97848,97849,97850,97853,97854,97857,97858,97861,97862))"
          }
        },
        {
          "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": 4,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "24.00",
              "eval_cost": "0.48",
              "prefix_cost": "53.09",
              "data_read_per_join": "12K"
            },
            "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": 4,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.20",
              "eval_cost": "0.48",
              "prefix_cost": "54.77",
              "data_read_per_join": "76"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}