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 = 7225 
WHERE 
  cscart_products_categories.product_id IN (
    91896, 90272, 86076, 86079, 86080, 90794, 
    90271, 90795, 91312, 91314, 91316, 
    86077, 86078, 90263, 90270, 90269, 
    90275, 90265, 93356, 93357, 93358, 
    93868, 93869, 93870, 93871, 94117, 
    94381, 94958, 95557, 95683, 95702, 
    95703, 95944, 96778, 96779, 96780, 
    96791, 96839, 96840, 96841, 96918, 
    96919, 96998, 98192, 98193, 98194, 
    98195, 98196
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00771

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "104.70"
    },
    "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": 116,
            "rows_produced_per_join": 116,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "11.90",
              "eval_cost": "11.60",
              "prefix_cost": "23.50",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (91896,90272,86076,86079,86080,90794,90271,90795,91312,91314,91316,86077,86078,90263,90270,90269,90275,90265,93356,93357,93358,93868,93869,93870,93871,94117,94381,94958,95557,95683,95702,95703,95944,96778,96779,96780,96791,96839,96840,96841,96918,96919,96998,98192,98193,98194,98195,98196))"
          }
        },
        {
          "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": 116,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "29.00",
              "eval_cost": "11.60",
              "prefix_cost": "64.10",
              "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": "29.00",
              "eval_cost": "0.58",
              "prefix_cost": "104.70",
              "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')))"
          }
        }
      ]
    }
  }
}