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 = 7257 
WHERE 
  cscart_products_categories.product_id IN (
    99063, 99064, 99065, 99067, 99077, 99078, 
    99081, 99082, 99110, 99111, 99112, 
    99113, 99114, 99115, 99116, 99117, 
    99118, 99119, 99120, 99121, 99122, 
    99123, 99124, 99125, 99126, 99127, 
    99128, 99129, 99130, 99131, 99132, 
    99134, 99135, 99143, 99144, 99162, 
    99163, 99164, 99165, 99166, 99168, 
    99171, 99172, 99173, 99174, 99175, 
    99176, 99177
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.01246

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "91.20"
    },
    "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": 101,
            "rows_produced_per_join": 101,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "10.40",
              "eval_cost": "10.10",
              "prefix_cost": "20.50",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (99063,99064,99065,99067,99077,99078,99081,99082,99110,99111,99112,99113,99114,99115,99116,99117,99118,99119,99120,99121,99122,99123,99124,99125,99126,99127,99128,99129,99130,99131,99132,99134,99135,99143,99144,99162,99163,99164,99165,99166,99168,99171,99172,99173,99174,99175,99176,99177))"
          }
        },
        {
          "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": 101,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "25.25",
              "eval_cost": "10.10",
              "prefix_cost": "55.85",
              "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": "25.25",
              "eval_cost": "0.51",
              "prefix_cost": "91.20",
              "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')))"
          }
        }
      ]
    }
  }
}

Result

product_id category_ids position
99063 7208M,7241,7309,7346
99064 7208M,7241,7309,7346
99065 7208M,7241,7309,7346
99067 7208M,7241,7309,7346
99077 7256M,7262
99078 7256M,7262
99081 7256M,7262
99082 7256M,7262
99110 7258M
99111 7259M,7345,7347
99112 7260M,7320
99113 7261M,7349
99114 7256M,7262
99115 7260M,7320
99116 7260M,7320
99117 7261M,7349
99118 7260M,7320
99119 7260M,7320
99120 7258M
99121 7258M
99122 7259M,7345,7347
99123 7258M
99124 7259M,7345,7347
99125 7258M
99126 7259M,7345,7347
99127 7258M
99128 7258M
99129 7259M,7345,7347
99130 7260M,7320
99131 7261M,7349
99132 7260M,7320
99134 7260M,7320
99135 7261M,7349
99143 7260M,7320
99144 7261M,7349
99162 7258M
99163 7259M,7345,7347
99164 7260M,7320
99165 7261M,7349
99166 7260M,7320
99168 7261M,7349
99171 7258M
99172 7259M,7345,7347
99173 7260M,7320
99174 7261M,7349
99175 7260M,7320
99176 7261M,7349
99177 7258M