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 = 7156 
WHERE 
  cscart_products_categories.product_id IN (
    96623, 96624, 96678, 96694, 97083, 97219, 
    97220, 97221, 97222, 97223, 97224, 
    97225, 97226, 97227, 97567, 97570, 
    97573, 97576, 97577, 97578, 97579, 
    97580, 97582, 97583, 97584, 97585, 
    97586, 97728, 97729, 97730, 97731, 
    97732, 97733, 97734, 97735, 97736, 
    97737, 97738, 97739, 97740, 97741, 
    97742, 97778, 97779, 97780, 97781, 
    97782, 97790, 97791, 97792, 97793, 
    97794, 97875, 97876, 97877, 97878, 
    97879, 97880, 97881, 97882, 97886, 
    97888, 98001, 98002, 98003, 98004, 
    98005, 98006, 98007, 98008, 98009, 
    98010, 98011, 98012, 98013, 98014, 
    98015, 98016, 98017, 98018, 98019, 
    98020, 98021, 98022, 98023, 98176, 
    98177, 98178, 98179, 98180, 98181, 
    98182, 98183, 98184, 98185, 98186
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00238

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "138.25"
    },
    "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": 243,
            "rows_produced_per_join": 243,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "24.65",
              "eval_cost": "24.30",
              "prefix_cost": "48.95",
              "data_read_per_join": "3K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (96623,96624,96678,96694,97083,97219,97220,97221,97222,97223,97224,97225,97226,97227,97567,97570,97573,97576,97577,97578,97579,97580,97582,97583,97584,97585,97586,97728,97729,97730,97731,97732,97733,97734,97735,97736,97737,97738,97739,97740,97741,97742,97778,97779,97780,97781,97782,97790,97791,97792,97793,97794,97875,97876,97877,97878,97879,97880,97881,97882,97886,97888,98001,98002,98003,98004,98005,98006,98007,98008,98009,98010,98011,98012,98013,98014,98015,98016,98017,98018,98019,98020,98021,98022,98023,98176,98177,98178,98179,98180,98181,98182,98183,98184,98185,98186))"
          }
        },
        {
          "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": 12,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "60.75",
              "eval_cost": "1.22",
              "prefix_cost": "134.00",
              "data_read_per_join": "31K"
            },
            "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": 12,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "3.04",
              "eval_cost": "1.22",
              "prefix_cost": "138.25",
              "data_read_per_join": "194"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}