SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd656af13211c63d0cc98ee432a71cef10dfc63e2570f7d22f2588842cee6009e' 
  AND token = 'cFKz9c6d/XLS211hTfGf/+1bevrYuEWQpMHLGpfHvCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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