If you can see your warrant online then certainly the CBP and a rental car company can. And the CBP will check: https://www.cbp.gov/travel/cbp-search-authority. They can hold you and contact the state to see if they want to extradite you to the state. If the answer is yes, then I would not want to be you. I doubt they would though, as Utah is unlikely to pay to send officers to pick you up and bring you back to the state so that you can appear for a speeding fine. Assuming the state does not want to extradite, it's not clear whether CBP will deny you entry to the US.

One question is whether they can clearly link you to the warrant. Does the warrant show your country, and either a DL number or passport number?

My own related anecdote: in 2018 I got a ticket for driving in a bus-only lane in Parma, Italy. I had no idea I had done that but they had a camera and I was apparently caught in the act. Hertz charged me their own processing fee for having to deal with the ticket but I was on my own for payng it. I never did, even though the city mailed notices to my house. In the fall of 2019 I again rented a car from Hertz in Italy (this time in Sicily) and had no problems.