The worlds two worst explorers sign themselves up for a tour of the Pyramids of Giza, only to them be trapped inside with a carpet salesman, a dentist, a phone salesman and the Pharaoh.

Basically you have devoted the entire longline to two things: the main characters and the inciting incident. The most important point is their intention over the course of the script. I suppose it's getting out of there. What could help to make this longline more appealing is to add some stakes and maybe a in impending clock that forces them to act fast. Also, are the people trapped inside maybe trying to stop them from getting out somehow, or are they all on their sides? Maybe one of these characters has reasons of their own not to let anybody get out of there?

The logline only describes a set up and an inciting incident. More information is need to flesh out a plot and a proper logline.

As a result of being trapped, what must the protagonist do?
(And why 2 explorers for protagonists instead of one? is this a buddy-film?)
Who/what stands in the way?
What's at stake?