SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66bcd37c3839549ce92dab97a290d0d312b3d5063222fb737c461030be7c15cc' 
  AND token = 'AdqWPlng3S8hiWJzlO/E8DUquvM/VOBd5Xa9yDIJEjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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