It seems very doable if you don't mind multiple PoDs-Muslim Spain has been discussed before and it seems maintainable if they win at Tours and the Franks get stuck in enough squabbling that the Cordobans can take out smaller potentially dangerous Christian kingdoms and done some internal housecleaning. Similar PoDs might accomplish both. Christian Asia Minor is also probably doable with a early PoD-possiblities include the Arabs being checked at the Yarmouk, slowing their conquest of Syria,more of an effort to expand into the ruins of the Sasanian empire to the east, or something on the lines of Bulgaria having awful internal troubles and Basil I/Nicephoros Phokas/John Tzimces/the other good rulers of that time period having more of a free hand to push the Arabs back to a more defensible frontier earlier and focus on firming up that boundary, with any of these very good emperors being able to institute the needed internal reforms.
As for slowing exploration, it could but that is something that would require a slowing of shipbuilding. It's the sort of thing that would really depend on how the timeline plays out I think. But the New World will be explored once you have good navigation and ships that can go the distance across the Atlantic and consistently get back OK.