To start this quest, examine one of the Empowered Life Shards. There is one in each of the two caves that contain the Treasure Vault Doors.
If the door does not highlight for you, move away from the door then re-approach it and it should be clickable. Clicking the door orders your pet troll to smash it. After it blows and kills the troll, step through and click on the chest to finish the quest and claim your Token of Gratitude.
This quest is a Daily and will reward the same amount of gold every time you do it, but you will get the Token of Gratitude the first time, only.