Monkey Quest was shut down in 2013, and there is no way to play the game or obtain items like trail keys.
If you're looking for similar games to Monkey Quest, you might consider:
* AdventureQuest Worlds: A free-to-play MMORPG with a similar cartoon style and focus on adventure.
* AQ3D: A 3D version of AdventureQuest Worlds with more action-oriented gameplay.
* DragonFable: Another free-to-play MMORPG with a fantasy setting and turn-based combat.
These games are all from the same developers as Monkey Quest and offer similar gameplay experiences.