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 (
    98479, 98480, 98481, 98483, 98484, 98490, 
    98492, 98759, 98769, 98770, 98771, 
    98772, 98831, 98832, 98833, 98834, 
    98835, 98836, 98837, 98838, 98839, 
    98840, 98841, 98842, 98843, 98844, 
    98845, 98846, 98847, 98848, 98849, 
    98850, 98897, 98914, 98915, 98916, 
    98917, 98918, 98919, 98920, 98921, 
    98922, 98923, 98924, 98925, 98926, 
    98927, 98928
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.01628

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "78.59"
    },
    "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": 87,
            "rows_produced_per_join": 87,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "8.99",
              "eval_cost": "8.70",
              "prefix_cost": "17.69",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (98479,98480,98481,98483,98484,98490,98492,98759,98769,98770,98771,98772,98831,98832,98833,98834,98835,98836,98837,98838,98839,98840,98841,98842,98843,98844,98845,98846,98847,98848,98849,98850,98897,98914,98915,98916,98917,98918,98919,98920,98921,98922,98923,98924,98925,98926,98927,98928))"
          }
        },
        {
          "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": 87,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "21.75",
              "eval_cost": "8.70",
              "prefix_cost": "48.14",
              "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": 4,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "21.75",
              "eval_cost": "0.44",
              "prefix_cost": "78.59",
              "data_read_per_join": "11K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}