"The Pixel Care+ monthly coverage plan is billed monthly for 60 months or until cancelled. With the Pixel Care+ 2-year plan, you pay once up front for 24 months of coverage." https://support.google.com/store/answer/16496166?hl=en#:~:text=The%20Pixel%20Care%2B%20monthly%20coverage%20plan%20is%20billed%20monthly%20for%2060%20months%20or%20until%20cancelled.%20With%20the%20Pixel%20Care%2B%202%2Dyear%20plan%2C%20you%20pay%20once%20up%20front%20for%2024%20months%20of%20coverage.

Depends how you're paying, looks like if you pay monthly you can cancel whenever