I had some of my macbook air's keys (escape and zero, which is closing bracket too) broken, and I'm too lazy to fix them. Instead I made this tray app, that copies broken keys' symbols to clipboard.
Press ⌘ + F11 to copy 0 in clipboard, ⌘ + F10 to copy ). If you use media keys (volume up / down), you have to press fn key as well.
Run npm install && npm start command to launch the app.