SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    22712, 22714, 22716, 22719, 22721, 22715, 
    22720, 22733, 22728, 22725, 22723, 
    22717, 22730, 22734, 22724, 22722, 
    22726, 22731, 22718, 22732, 22713, 
    22727, 22729
  ) 
  AND category_id != 1

Query time 0.00006

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": 23,
          "filtered": 100,
          "index_condition": "cscart_categories.parent_id in (22712,22714,22716,22719,22721,22715,22720,22733,22728,22725,22723,22717,22730,22734,22724,22722,22726,22731,22718,22732,22713,22727,22729)",
          "attached_condition": "cscart_categories.category_id <> 1"
        }
      }
    ]
  }
}