SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'fb55e35f5a5c051c0333bce1adbd80ab5bb365eb08843539c880aca4dc3e6bd3' 
  AND token = 'G1iTuONq5hMD0snDZZiPb9iZ812WqrNkivxdGpavGYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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