Hi, Katie!
Wow! What a great choice!
Disney's Keys to the Kingdom Tour is a Guest favorite, so I know you are in for a magically amazing time.
If you have enabled charges to be made to your room (dining, for example, in addition to these tickets) then you can pay for any portion of those charges right at the front desk, using cash, credit card or Disney Gift Cards. We booked a 3-bedroom Grand Villa last summer and had been given cash and gift cards by other family members staying with us, to pay for the Dining Plan and other such things.) I simply headed to the front desk from time to time to pay off some of the balance, keeping that charge from being applied to my credit card. If you'd like, the Cast Member assisting you can even provide you with a printout of charges and payments made as well. It's very simple and hassle-free!
Have a wonderful trip and a spectacular tour, Katie!
Be sure to send more questions as you think of them, too. We love to help!