Electronic tokens have been proved as an effective incentive scheme in stimulating self-interested network nodes to transmit other nodes' traffic. In other words, tokens are paid to buy transmission. In this work, we propose a novel token framework in a distributed small cell network and design the token system for improved interference mitigation. Contrary to the traditional role of tokens for buying transmission, they are exchanged between users to buy 'silence'. We focus on designing the optimal token system that minimizes the system outage probability. We first analyze the optimal strategies of individual users, which only consider their own utility maximization and do not care about the system-wise performance. We show that under some mild conditions the optimal strategy has a simple threshold structure. We then analytically derive the optimal token supply that minimizes the network outage probability. Simulation results show that not only does the proposed token system design greatly improve the network outage probability (by up to 75%), it also improves the overall small cell network QoS, particularly when the deployment density is high.