Hive'Zora glyphed crystal location:

Take the cave entrance at the most south-eastern corner of the hive. Once you're in the cave, finding the crystal is simple; follow the cave right through to the eastern most end. The crystal is in the center of the round room filled with non-elite wasps. Easily soloed as a rogue, but I have no idea for other classes.

Once you're standing at the crystal, the aggro range on the wasps isn't large enough for them to see you (they are round the outside of the room), so you won't need your vanish cooldown.