You don't pay a royalty rate, the artist receives one.
What you pay is a licensing fee, and this will vary according to the use--recorded reproduction, online, or live--and the organization administering the license in question.
So, you'd have to find out who administers the rights for "Viva la Vida" where you will be using it, and find out what their licensing terms are. In the US, the main organizations are BMI and ASCAP, so I'd start by checking out their websites; they have databases of songs that they administer so you can contact them about licensing.
I know it's complicated, but that's why there are so many entertainment lawyers...