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 = 7210 
WHERE 
  cscart_products_categories.product_id IN (
    88566, 87617, 87625, 87890, 88673, 88720, 
    88401, 84695, 87283, 87291, 88937, 
    87877, 87905, 88045, 88049, 88565, 
    88564, 87936, 87636, 88515, 88518, 
    89107, 89114, 88078, 88514, 88517, 
    90832, 88511, 87621, 87623, 88083, 
    88671, 88718, 87635, 87904, 90325, 
    87806, 87807, 87812, 87815, 87821, 
    87638, 87640, 87876, 88506, 88507, 
    88510, 88035, 88044, 87987, 90828, 
    87632, 88561, 87637, 90827, 87938, 
    87941, 87997, 88026, 87764, 87770, 
    87773, 87777, 87781, 87788, 87794, 
    87281, 87289, 87882, 87988, 88036, 
    88047, 88048, 86862, 90324, 90326, 
    88050, 88051, 88052, 88053, 88054, 
    87900, 87901, 87990, 87961, 88088, 
    87875, 87937, 90323, 87950, 87959, 
    88798, 90826, 87754, 87952, 88004
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00293

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "158.69"
    },
    "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": 279,
            "rows_produced_per_join": 279,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "28.26",
              "eval_cost": "27.90",
              "prefix_cost": "56.16",
              "data_read_per_join": "4K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (88566,87617,87625,87890,88673,88720,88401,84695,87283,87291,88937,87877,87905,88045,88049,88565,88564,87936,87636,88515,88518,89107,89114,88078,88514,88517,90832,88511,87621,87623,88083,88671,88718,87635,87904,90325,87806,87807,87812,87815,87821,87638,87640,87876,88506,88507,88510,88035,88044,87987,90828,87632,88561,87637,90827,87938,87941,87997,88026,87764,87770,87773,87777,87781,87788,87794,87281,87289,87882,87988,88036,88047,88048,86862,90324,90326,88050,88051,88052,88053,88054,87900,87901,87990,87961,88088,87875,87937,90323,87950,87959,88798,90826,87754,87952,88004))"
          }
        },
        {
          "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": 13,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "69.75",
              "eval_cost": "1.40",
              "prefix_cost": "153.81",
              "data_read_per_join": "36K"
            },
            "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": 13,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "3.49",
              "eval_cost": "1.40",
              "prefix_cost": "158.69",
              "data_read_per_join": "223"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}