Keys are found in dungeons and as quest rewards. They are used to open chests on street view.
Your stock of keys cannot be seen anywhere in the profile, but there are two ways to check the quantity of keys you possess:
- In Map view, click on the Store icon in the bottom left and click Boosts, then select the Keys tab at the bottom. On the right half of the screen, below the Key image, it will list the number of keys in your possession. You can also buy 10 keys for 10.
- When a locked chest is being opened the current number of keys is displayed.