SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ec7dcae2b5c989ff1169562cf29b017417b921b9dc537458d0a499b0720c55b' 
  AND token = 'HN7KyNhJhsrUQmVZLwfDuWMMz24doUzGBzhyn5OkdpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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