In a world that has changed drastically because of COVID-19, Mexico's entry restrictions seem to not be effected. Currently the only change to Mexico's entry restrictions, by air, is that passengers will go through temperature checks and fill out a diagnostic questionnaire. This has made vacations to Mexico very popular right now.
Entry by land is still currently restricted, unless you are an essential worker, but that may open up by the end of November.
For more information please see the U.S. State Department's site for Mexico.