In most countries, you can pay by any major credit card on a per-order basis via PayPal without actually creating a PayPal account. Simply choose "Checkout with PayPal or a credit card when your order is ready" during checkout, or via My Account like any other e-commerce site. You'll be sent directions on how to pay by credit card via PayPal when it's time to pay. Please note again that this must be done each time, on a per-order basis. All credit card processing and data management will be handled by PayPal; HLJ does not accept or store any credit card information.
Please be aware that if you have a PayPal Billing Agreement in place you will not be able to pay through the "Checkout with PayPal or a credit card when your order is ready" method even if you select it at checkout.
For more information, please see this page.