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 = 7200 
WHERE 
  cscart_products_categories.product_id IN (
    84651, 84585, 84631, 84621, 84677, 84321, 
    84499, 84565, 84489, 84555, 84545, 
    84611, 84301, 84291, 84667, 84347, 
    84535, 84601, 84546, 84612, 84348, 
    101134, 101135, 101136, 101137, 101138, 
    101139, 101140, 101141, 101142, 101143, 
    101144, 101145, 101146, 101147, 101148, 
    101149, 101150, 101151, 101152, 101153, 
    101154, 101155, 101156, 101157, 101158, 
    101159, 101160, 101161, 101162, 101163, 
    101164, 101165, 101166, 101167, 101168, 
    101169, 101170, 101171, 101172, 101173, 
    101174, 101175, 101176, 101177, 101178, 
    101179, 101180, 101181, 101182, 101183, 
    101184, 101185, 101186, 101187, 101188, 
    101189, 101190, 101191, 101192, 101193, 
    101194, 101195, 101196, 101197, 101198, 
    101199, 101200, 101201, 101202, 101203, 
    101204, 101205, 101206, 101207, 101208
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00360

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "66.70"
    },
    "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": 117,
            "rows_produced_per_join": 117,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "12.00",
              "eval_cost": "11.70",
              "prefix_cost": "23.70",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (84651,84585,84631,84621,84677,84321,84499,84565,84489,84555,84545,84611,84301,84291,84667,84347,84535,84601,84546,84612,84348,101134,101135,101136,101137,101138,101139,101140,101141,101142,101143,101144,101145,101146,101147,101148,101149,101150,101151,101152,101153,101154,101155,101156,101157,101158,101159,101160,101161,101162,101163,101164,101165,101166,101167,101168,101169,101170,101171,101172,101173,101174,101175,101176,101177,101178,101179,101180,101181,101182,101183,101184,101185,101186,101187,101188,101189,101190,101191,101192,101193,101194,101195,101196,101197,101198,101199,101200,101201,101202,101203,101204,101205,101206,101207,101208))"
          }
        },
        {
          "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": "29.25",
              "eval_cost": "0.59",
              "prefix_cost": "64.65",
              "data_read_per_join": "15K"
            },
            "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": 5,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.46",
              "eval_cost": "0.59",
              "prefix_cost": "66.70",
              "data_read_per_join": "93"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}