PayPal Express Checkout Payment gateway allows you to have credit/debit card icons to be placed at the checkout page beside the PayPal payment option as shown below:
You can make use of a filter to remove or hide these card icons. Simply insert the below-given code snippet into functions.php of the active theme file.
On inserting the filter, you can see that the card icons are removed from the checkout page as shown below.
You can learn more about the plugin by viewing this short set up tutorial on PayPal express checkout payment gateway.