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 (
    87078, 87123, 87124, 87125, 87126, 87127, 
    87128, 87129, 91115, 91117, 91121, 
    91123, 91126, 91128, 91130, 91201, 
    91203, 91207, 91209, 91212, 91214, 
    91216, 91256, 91258, 91262, 91264, 
    91267, 91269, 91271, 86906, 86907, 
    86908, 86909, 86910, 86911, 86967, 
    86968, 86969, 86970, 86971, 86972, 
    87028, 87029, 87030, 87031, 87032, 
    87033, 87087, 87088, 87089, 87090, 
    87091, 87092, 91146, 91148, 91152, 
    91154, 91157, 91159, 91161, 86920, 
    86921, 86922, 86923, 86924, 86925, 
    86926, 86981, 86982, 86983, 86984, 
    86985, 86986, 86987, 87042, 87043, 
    87044, 87045, 87046, 87047, 87048, 
    87100, 87101, 87102, 87103, 87104, 
    87105, 87106, 84640, 84641, 84508, 
    84509, 84574, 84575, 86913, 86914
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00192

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "105.88"
    },
    "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": 186,
            "rows_produced_per_join": 186,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "18.93",
              "eval_cost": "18.60",
              "prefix_cost": "37.53",
              "data_read_per_join": "2K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (87078,87123,87124,87125,87126,87127,87128,87129,91115,91117,91121,91123,91126,91128,91130,91201,91203,91207,91209,91212,91214,91216,91256,91258,91262,91264,91267,91269,91271,86906,86907,86908,86909,86910,86911,86967,86968,86969,86970,86971,86972,87028,87029,87030,87031,87032,87033,87087,87088,87089,87090,87091,87092,91146,91148,91152,91154,91157,91159,91161,86920,86921,86922,86923,86924,86925,86926,86981,86982,86983,86984,86985,86986,86987,87042,87043,87044,87045,87046,87047,87048,87100,87101,87102,87103,87104,87105,87106,84640,84641,84508,84509,84574,84575,86913,86914))"
          }
        },
        {
          "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": "46.50",
              "eval_cost": "0.93",
              "prefix_cost": "102.63",
              "data_read_per_join": "24K"
            },
            "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": "2.33",
              "eval_cost": "0.93",
              "prefix_cost": "105.88",
              "data_read_per_join": "148"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}