SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '664804452e1668d62cee865ba8631396ec82ca0c21f4093cf8cbbaae59932f33' 
  AND token = 'MyQvwRSFiDIv1jS1pKFBeoI+C/NggthILv0pbvVD0Os=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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