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 = 7234 
WHERE 
  cscart_products_categories.product_id IN (
    86313, 86329, 86259, 86307, 86297, 86323, 
    86267, 86288, 86302, 86315, 86295, 
    86301, 86314, 86321, 86265, 86286, 
    86293, 86319, 86263, 86284, 95165, 
    95168, 95171, 95173, 95177, 95179, 
    95181, 95187, 95189, 95195, 95197, 
    95201, 95203, 95205, 95213, 95215, 
    95219, 95222, 95224, 95227, 95230, 
    95232, 95234, 95236, 95238, 95240, 
    95242, 95244, 96050, 96052, 96054, 
    96056, 96058, 96060, 96063, 96065, 
    96067, 96069, 96071, 96073, 96075, 
    96077, 96079, 96080, 96081, 96084, 
    96085, 96088, 96089, 96092, 96093, 
    96096, 96097, 96100, 96101, 96104, 
    96394, 96395, 96396, 96397, 96409, 
    96410, 96429, 96432, 96433, 96442, 
    96443, 96444, 96445, 96446, 96447, 
    96448, 96449, 96450, 96451, 96452
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00338

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "54.77"
    },
    "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": 96,
            "rows_produced_per_join": 96,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "9.89",
              "eval_cost": "9.60",
              "prefix_cost": "19.49",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (86313,86329,86259,86307,86297,86323,86267,86288,86302,86315,86295,86301,86314,86321,86265,86286,86293,86319,86263,86284,95165,95168,95171,95173,95177,95179,95181,95187,95189,95195,95197,95201,95203,95205,95213,95215,95219,95222,95224,95227,95230,95232,95234,95236,95238,95240,95242,95244,96050,96052,96054,96056,96058,96060,96063,96065,96067,96069,96071,96073,96075,96077,96079,96080,96081,96084,96085,96088,96089,96092,96093,96096,96097,96100,96101,96104,96394,96395,96396,96397,96409,96410,96429,96432,96433,96442,96443,96444,96445,96446,96447,96448,96449,96450,96451,96452))"
          }
        },
        {
          "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": 4,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "24.00",
              "eval_cost": "0.48",
              "prefix_cost": "53.09",
              "data_read_per_join": "12K"
            },
            "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": 4,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.20",
              "eval_cost": "0.48",
              "prefix_cost": "54.77",
              "data_read_per_join": "76"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}