Real Buddy (2014) on Netflix

Plot summary

Morris has served six and a half years for fraud in the toughest prison of the near future, and his last day inside has come. Five million dollars of his money is hidden within the prison walls, and he cannot wait to collect it and start a bright future on the outside. His fellow inmates want that money for themselves and keep trying to get it from him, so he guards its location and keeps his cell buddy at his side. Beyond the walls, the world may be ending, and he hopes it is still there when he walks out.