Mexico allows entry if you have a valid stamped US or Canadian visa in your passport.
The visa should be valid for the duration of your stay in Mexico.
If you do not have a stamped visa in your passport, then you should get a Mexican tourist visa before traveling to Cancun.
Example 1
You have an H1B visa stamped in your passport and it is valid for another 1 month. Mexico will allow you to enter Cancun for up to 1 month.
Example 2
You have an expired H1B visa but a valid approved H1B i797. Mexico will NOT allow entry as their rule requires you to have a valid stamped visa in your passport.
Traveling back to USA
USA will allow entry based on approved AP. You may need extra time at the airport/land border as every advance parole entry needs a secondary inspection.
It can take anywhere between 1-3 hours based on the secondary inspection queue at the airport at that time.