You can use this module with the following in your ~/.xmonad/xmonad.hs:

 import XMonad.Prompt
 import XMonad.Prompt.Theme

in your keybindings add:

   , ((modMask x .|. controlMask, xK_t), themePrompt defaultXPConfig)

For detailed instruction on editing the key binding see XMonad.Doc.Extending#Editing_key_bindings.