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 = 7170 
WHERE 
  cscart_products_categories.product_id IN (
    85257, 89242, 83071, 83072, 83624, 83625, 
    90907, 90908, 90986, 90987, 85082, 
    85168, 85214, 85260, 83038, 90874, 
    90953, 82622, 85119, 85122, 86189, 
    86212, 86521, 86797, 90564, 90570, 
    90576, 89073, 83069, 83622, 90905, 
    90984, 85080, 85166, 85212, 85258, 
    86193, 86194, 86216, 86217, 86525, 
    86526, 86801, 86802, 84678, 87304, 
    87305, 87316, 87317, 87328, 87329, 
    87340, 87341, 85120, 87310, 87311, 
    87322, 87323, 87334, 87335, 87346, 
    87347, 84654, 84655, 89818, 89819, 
    89870, 89871, 89942, 89943, 91508, 
    91509, 83083, 83084, 83611, 83612, 
    86144, 86145, 86167, 86168, 86660, 
    86661, 86729, 86730, 90922, 90923, 
    91001, 91002, 87298, 87299, 87292, 
    87293, 84527, 84528, 84593, 84594
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00247

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "98.50"
    },
    "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": 173,
            "rows_produced_per_join": 173,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "17.62",
              "eval_cost": "17.30",
              "prefix_cost": "34.92",
              "data_read_per_join": "2K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (85257,89242,83071,83072,83624,83625,90907,90908,90986,90987,85082,85168,85214,85260,83038,90874,90953,82622,85119,85122,86189,86212,86521,86797,90564,90570,90576,89073,83069,83622,90905,90984,85080,85166,85212,85258,86193,86194,86216,86217,86525,86526,86801,86802,84678,87304,87305,87316,87317,87328,87329,87340,87341,85120,87310,87311,87322,87323,87334,87335,87346,87347,84654,84655,89818,89819,89870,89871,89942,89943,91508,91509,83083,83084,83611,83612,86144,86145,86167,86168,86660,86661,86729,86730,90922,90923,91001,91002,87298,87299,87292,87293,84527,84528,84593,84594))"
          }
        },
        {
          "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": 8,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "43.25",
              "eval_cost": "0.87",
              "prefix_cost": "95.47",
              "data_read_per_join": "22K"
            },
            "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": 8,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "2.16",
              "eval_cost": "0.87",
              "prefix_cost": "98.50",
              "data_read_per_join": "138"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}