Bare bones SNAKE game
There are two main issues with your code.

Comments

Explain your code and what you are trying to do. If you keep developing this game, after some time you will have problems to understand what you are doing.

Especially explain the move_snake(), kill_snake() and feed_snake() functions, but also the usage of the variables.

Constants

Rename all constants, like keys to KEYS.

Access all constants with e.g. Snake.KEYS because they are constants, no class variables that are different for every instance.

To improve readability, you can change the indention for KEYS like this:

KEYS = {"GO": pygame.KEYDOWN,
        "UP": pygame.K_UP, 
        "DOWN": pygame.K_DOWN, 
        "LEFT": pygame.K_LEFT, 
        "RIGHT": pygame.K_RIGHT }