Boost Tokens, or simply Tokens, are items earned in Contracts after set intervals of time and from some Boxes and Videos.
Each Boost you own requires a certain number of Tokens to be used on a Contract (details can presently be found on the Boosts page). Tokens do not need to be used to use Boosts on normal (non-Contract) farms.
Strategy[]
Token Farming Strategy[]
The best, and only way to token farm is to wait for gift boxes and video ads. Keeping your habs full, or close to full, also helps as it takes chicken boxes out of the reward rotation. ULTRA Pro players can also farm tokens more efficiently as they can receive tokens immediately without waiting for a full 30 second ad to play.
Boosting Strategies[]
4 Tokens[]
The 4 Token combo is 2 Epic Tachyon Prisms (100x internal hatchery for 2 hours). Ran together, while off farm (to make full use of Internal Hatchery Calm), will net you just over 2.1 billion chickens, leaving aside the effects of Artifacts.
The 4 Token Combo can also be 1 Supreme Tachyon Prism (1000x Internal Hatchery for 1 hour). Run with early free tachs and a decent IHR and Dilithium set, and it will fill your habs.
5 Tokens[]
The 5 Token Combo is 1 Epic Tachyon Prism (100x IH for 2 hours) and 3x Boost Beacons (2x active boosts for 30 minutes), for the cost of 6400 
.The Boost Beacons can either be ran simultaneously (Pro Permit), or one after another (Standard Permit), while off farm (to make use of Internal Hatchery Calm), to net you 2.4 billion chickens (ignoring Artifacts, assuming max relevant Epic Research).
Typically used for AAA contracts, this is usually followed by farming Chicken Boxes, via ads, to fill your habs.
8 Tokens[]
A popular late game strategy to quickly increase one's hourly rate is called the '8 token combination', '8 token strategy' or simply '8 token'. This involves the use of a Legendary Tachyon Prism, an Epic Boost Beacon and the fully researched version of the Epic Int. Hatcheries and Internal Hatchery Calm Epic Researches. When all of these factors are combined, assuming you've purchased all levels of IHR Common Research for a base of 7,440 IHR/minute/habitat, the result is a population of 8,928,000,000 chickens.
The end result assumes you go offline for the full duration of the boosts, and does not take into account the effect of Artifacts. After using this combination, any remaining Habitat space can be filled with Chicken Boxes, assuming one's Habitats are not 90% or more full.