SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '16a08e091fd17ae07f7f1884a716c10d357b2e6232dd67e402cd05a28222ee56' 
  AND token = '5ven+CqAYJM5HFiZPXeOPh/ehFD+sD6nIEURHzplsUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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