It isn't in DrRacket by default but it is a common enough requested feature that they keep an example of how to add it in the documentation.
https://docs.racket-lang.org/drracket/Keyboard_Shortcuts.htm...
https://docs.racket-lang.org/drracket/Keyboard_Shortcuts.htm...
http://docs.racket-lang.org/guide/eval.html?q=namespace#%28p...