Rebind focus pane shortcuts

Hi,

I would like to rebind the original

'body':
  'cmd-k cmd-up': 'focus-pane-or-panel:focus-above'
  'cmd-k cmd-down': 'focus-pane-or-panel:focus-below'
  'cmd-k cmd-left': 'focus-pane-or-panel:focus-on-left'
  'cmd-k cmd-right': 'focus-pane-or-panel:focus-on-right'

To use alt+up/left/down/right combinations. However, after editing this in keymap.cson it does not have an effect.