Is there a keyboard shortcut for "Show Hidden Files" in the Finder in El Cap?
There's no shortcut.
You could make one, but it would require a Automator action, containing a script, and set up as a Service, &amp; will re-launch the Finder each time it's used. [Mavericks could do it without relaunch but no other OS] 

For the number of times I actually use it, I just keep the script accessible instead.

--Toggle Invisibles
set newHiddenVisiblesState to "YES"
try
    set oldHiddenVisiblesState to do shell script "defaults read com.apple.finder AppleShowAllFiles"
    if oldHiddenVisiblesState is in {"1", "YES"} then
        set newHiddenVisiblesState to "NO"
    end if
end try
do shell script "defaults write com.apple.finder AppleShowAllFiles " &amp; newHiddenVisiblesState &amp; "; killall Finder"


Copy paste to Script Editor &amp; save as an App.
It will toggle visible state each time it's launched.