Can you prevent the lockout screen from occurring during display sleep when streaming to chromecast?

On my MBP, if I'm streaming something to the chromecast for any appreciable length of time the display sleeps. That's not a bad thing, it's supposed to do that, but the trouble is, if I want to pause playback, it's not a matter of simply hitting the pause key to immediately pause. This is because pressing any key wakes up the display and presents the login prompt.

To pause, I have correctly type in my password, and then in the appropriate app hit the pause button. This process takes several seconds and if I needed to pause because of wanting to freeze on something I'm viewing, or because something around me is happening that demands immediate halt to playback for me to attend to it, then this lag between the decision to pause and when I've finally paused is really just way too long. To make it worse, if I'm streaming youtube and this happens, the playback controls presented via the browser on the video page stop controlling the chromecast stream, the pause key does nothing. I can eventually pause (though not seek) via the player notification controls but it's not ideal.