Here is the default configuration file: Standard (Windows) .sublime-keymap
And here is the line that creates this shortcut:
{ "keys": ["ctrl+k", "l"], "command": "sublimelinter_lint" },
This means that you press ctrl+ k, and then press l. This is a sequence binding, which you can also do in your custom key file.
Be sure to ctrllet go by pressing l.
P.S. L, i. ? , ctrl + k, ctrl + u.
: { "keys": ["ctrl+k", "ctrl+u"], "command": "upper_case" },