Express Checkout

We are working on an effortless single page checkout for returning customers, for expert user cohort.

The flow is triggered from "Buy Now" button and all important and needed information has been manifested in a single page that is starting from the top, platform currency application, product summary, preferred saved address and preferred save payment method.

I'm facing a challenge in the payment method, I want to form a connection between the cvv field, the total amount and the "Pay Now" button. I tried a design previously but I got a feedback that user might not understand that he has to enter something here hence I made a new design but I wasn't much convinced with the new design.

Also in order to place an order via Cash On Delivery, user has to enter the characters shown in the captcha, tried few variations but wasn't convinced with the final design.

Can someone please suggest a better way to present the total amount, cvv text field and "pay now" button, same for the cash on delivery variation.