SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '232de9054b898225397e850fe87c7695a4411ba58b5ff770f5a9ed7a59983576' 
  AND token = 'hzmlcLQ9uwJ9xJrPmNCOzk2VeWLE4CuChHGq3sKvldo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}