A short note straight from the WoT website:
This Sandbox test has ended. We are currently transferring tokens to the main server and you will be able to spend them in a special section of the in-game store for rewards. Make sure to collect your Tokens in the Warehouse before going to the store. Remember to spend your tokens before starting the next test, otherwise they will be exchanged for credits at a rate of 1 token = 10,000 credits.