SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ed889d43f9051c629fdaf35b0cd95641ac170fbb72b573bfb9c3b3f12db339c' 
  AND token = 'IpJd+dxMeooDbG04uKD/pWsXeSqDYiPodojGV8xAj7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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