SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99799eaa824ae28473c044870e08f587cc92fd1ed9da4a864b5bd3b7f8455a3d' 
  AND token = 'WEUwNlp4VYcklOcXIGnIh/u9RW+5w8hmfXXhM4k8YQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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