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 = 7197 
WHERE 
  cscart_products_categories.product_id IN (
    84708, 84749, 84731, 84732, 84733, 87921, 
    87923, 87933, 87935, 88042, 84720, 
    84723, 84727, 87974, 84271, 84939, 
    84734, 84735, 84938, 84719, 84722, 
    84724, 84744, 84718, 84721, 84937, 
    84936, 87991, 87966, 87922, 87928, 
    87934, 88017, 84856, 84857, 84949, 
    84950, 84690, 84748, 88039, 87905, 
    84691, 87894, 84847, 84854, 84855, 
    87906, 84689, 84945, 84946, 91064, 
    84270, 88033, 88007, 84754, 84755, 
    84943, 84944, 87904, 87910, 87911, 
    87912, 87896, 88034, 84269, 84958, 
    87892, 87897, 84952, 84953, 87909, 
    87916, 87891, 87895, 87903, 87908, 
    87914, 84746, 87893, 87963, 84959, 
    87913, 87917, 88036, 87971, 84756, 
    84757, 88016, 84861, 84862, 87900, 
    87901, 87915, 88088, 88056, 88057
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.01649

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "93.90"
    },
    "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": 104,
            "rows_produced_per_join": 104,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "10.70",
              "eval_cost": "10.40",
              "prefix_cost": "21.10",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (84708,84749,84731,84732,84733,87921,87923,87933,87935,88042,84720,84723,84727,87974,84271,84939,84734,84735,84938,84719,84722,84724,84744,84718,84721,84937,84936,87991,87966,87922,87928,87934,88017,84856,84857,84949,84950,84690,84748,88039,87905,84691,87894,84847,84854,84855,87906,84689,84945,84946,91064,84270,88033,88007,84754,84755,84943,84944,87904,87910,87911,87912,87896,88034,84269,84958,87892,87897,84952,84953,87909,87916,87891,87895,87903,87908,87914,84746,87893,87963,84959,87913,87917,88036,87971,84756,84757,88016,84861,84862,87900,87901,87915,88088,88056,88057))"
          }
        },
        {
          "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": 104,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "26.00",
              "eval_cost": "10.40",
              "prefix_cost": "57.50",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        },
        {
          "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": 5,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "26.00",
              "eval_cost": "0.52",
              "prefix_cost": "93.90",
              "data_read_per_join": "13K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}