SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89914c453b8f39303daaa0859565726a4130e6459b398845c65116168d50fc47' 
  AND token = 'qJBlEJ8p8iZuuvs7VKDiovjmff+M6KV+zwa9GQvmZK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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