Moab is just over a 3.5 hour drive from Salt Lake City.
The SLC airport is the largest airport servicing Moab. It has multiple direct flights daily from both Boston and New York City. Once you arrive you can explore the many great things SLC has to offer before driving the 3 hours and 40 minutes to Moab.
If you're looking for a shorter drive, Grand Junction may be an option. The drive from this Colorado-based airport to Moab is 1 hour and 45 minutes. This is a smaller airport, so flights are more expensive and direct flight options are limited.