SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    22849, 22847, 22856, 22846, 22855, 22841, 
    22850, 22853, 22842, 22840, 22848, 
    22851, 22852, 22845, 22854, 22843, 
    22844
  ) 
  AND category_id != 1

Query time 0.00004

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_categories",
          "access_type": "range",
          "possible_keys": ["PRIMARY", "parent", "p_category_id"],
          "key": "parent",
          "key_length": "3",
          "used_key_parts": ["parent_id"],
          "rows": 17,
          "filtered": 100,
          "index_condition": "cscart_categories.parent_id in (22849,22847,22856,22846,22855,22841,22850,22853,22842,22840,22848,22851,22852,22845,22854,22843,22844)",
          "attached_condition": "cscart_categories.category_id <> 1"
        }
      }
    ]
  }
}