SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    309, 439, 291, 283, 286, 442, 370, 301
  )

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_categories",
      "access_type": "ALL",
      "possible_keys": ["parent"],
      "rows": 217,
      "filtered": 23.0414753,
      "attached_condition": "cscart_categories.parent_id in (309,439,291,283,286,442,370,301)"
    }
  }
}