The conntent of .emulator_console_auth_token might be something like
LSoNKBoN4ql6TuLi
This value is used when connecting to an Android Emulator with telnet (Android Console):
C:\> telnet localhost 5554
Android Console: Authentication required
Android Console: type 'auth <auth_token>' to authenticate
Android Console: you can find your <auth_token> in
'C:\Users\Rene\.emulator_console_auth_token'
OK
auth LSoNKBoN4ql6TuLi
Android Console: type 'help' for a list of commands
OK