Org does not provide any markup for key bindings that corresponds to
Texinfo’s @kbd and @key commands. One way to deal with this is to
fall back to code syntax. ‘~C-x SPC~’, for example, is transcoded to
@code{C-x SPC}.
A better approach is to define and use an Org macro named kbd. To
make that easier the function org-texinfo-kbd-macro is provided,
which is intended to be used like this:
#+macro: kbd (eval (org-texinfo-kbd-macro $1))
Type {{{kbd(C-c SPC)}}}.
which becomes
Type @kbd{C-c @key{SPC}}.