This planet is a rogue planet without any star or without being volcanically active. Antimatter continually collides with the planet, and annihilates with hydrogen in the upper atmosphere. This provides heat and light for the planet.
Alternatively, the planet could be made out of antimatter, with regular matter colliding with it. The end result is the same.
Could these conditions allow the planet to support life and allow enough time for life to evolve (10-20 million years)?