Yes, as long as the cantrip has a casting time of 1 Action

Most cantrips require an action to cast. As such, you can certainly quicken them. So any 1 Action casting time cantrip will be usable, such as Eldritch Blast in this question.

However, PHB p. 202 states:

A spell cast with a bonus action is especially swift. You must use a bonus action on your turn to cast the spell, provided that you haven't already taken a bonus action this turn. You can't cast another spell during the same turn, except for a cantrip with a casting time of 1 action.

Thankfully, if you are planning on casting two cantrips per turn, you are more than able to do this effectively, as they are not restricted by the same restriction as regular spells.

You can only cast them once per long rest

As you quoted above, you can only cast each spell once per long rest. A cantrip is still a spell (just at 0 level, which would be the lowest level you cast it as) and therefore falls under the same requirement.

Counter-examples

Dragonmark differs in its language and requirements from things like the Magic Initiate Feat or The cantrips gained from a certain race (like High-elf.) Those simply add that cantrip to your current list and do not have a limitation on uses/day.