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 = 7171 
WHERE 
  cscart_products_categories.product_id IN (
    91125, 91127, 91129, 91200, 91202, 91206, 
    91208, 91211, 91213, 91215, 91255, 
    91257, 91261, 91263, 91266, 91268, 
    91270, 85352, 85354, 91145, 91147, 
    91151, 91153, 91156, 91158, 91160, 
    82811, 82813, 82884, 82886, 82957, 
    82959, 83331, 83333, 83341, 83343, 
    89493, 89494, 89501, 89502, 89509, 
    89510, 89517, 89518, 82592, 82594, 
    83355, 83357, 86630, 86632, 86699, 
    86701, 82822, 82824, 82895, 82897, 
    82968, 82970, 86190, 86191, 86213, 
    86214, 86522, 86523, 86798, 86799, 
    86188, 86211, 86520, 86796, 82603, 
    82605, 83071, 83072, 83624, 83625, 
    90907, 90908, 90986, 90987, 85082, 
    85168, 85214, 85260, 85122, 86189, 
    86212, 86521, 86797, 89073, 83069, 
    83622, 90905, 90984, 85080, 85166
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00109

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "109.29"
    },
    "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": 192,
            "rows_produced_per_join": 192,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "19.53",
              "eval_cost": "19.20",
              "prefix_cost": "38.73",
              "data_read_per_join": "3K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (91125,91127,91129,91200,91202,91206,91208,91211,91213,91215,91255,91257,91261,91263,91266,91268,91270,85352,85354,91145,91147,91151,91153,91156,91158,91160,82811,82813,82884,82886,82957,82959,83331,83333,83341,83343,89493,89494,89501,89502,89509,89510,89517,89518,82592,82594,83355,83357,86630,86632,86699,86701,82822,82824,82895,82897,82968,82970,86190,86191,86213,86214,86522,86523,86798,86799,86188,86211,86520,86796,82603,82605,83071,83072,83624,83625,90907,90908,90986,90987,85082,85168,85214,85260,85122,86189,86212,86521,86797,89073,83069,83622,90905,90984,85080,85166))"
          }
        },
        {
          "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": 9,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "48.00",
              "eval_cost": "0.96",
              "prefix_cost": "105.93",
              "data_read_per_join": "25K"
            },
            "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": 9,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "2.40",
              "eval_cost": "0.96",
              "prefix_cost": "109.29",
              "data_read_per_join": "153"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}