SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    274, 2490, 2310, 58, 2528, 133, 66, 167, 
    2818, 2694, 2489, 90, 335, 2649, 128, 
    157, 233, 62, 72, 112, 3099, 2862
  )

Query time 0.00136

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_categories",
      "access_type": "range",
      "possible_keys": ["parent"],
      "key": "parent",
      "key_length": "3",
      "used_key_parts": ["parent_id"],
      "rows": 326,
      "filtered": 100,
      "index_condition": "cscart_categories.parent_id in (274,2490,2310,58,2528,133,66,167,2818,2694,2489,90,335,2649,128,157,233,62,72,112,3099,2862)"
    }
  }
}