I had same issue. The solution I came up with is using Autohotkey.
Install Autohotkey from here and save following script as tmp.ahk
and execute the file by clicking.
You can rewind Youtube videos for 1 second by z
and forward Youtube videos for 1 second by x
.
SetTitleMatchMode, regex
SetTitleMatchMode, Slow
#If WinActive("ahk_exe chrome.exe") && WinActive(" - YouTube")
z::
send, +<+<+<{left}+>+>+>
return
x::
; msgbox,
send, +<+<+<{right}+>+>+>
return
#If
WinActive("ahk_exe chrome.exe")
: The feature will be only enabled on chrome.exe
WinActive("YouTube")
: The feature will be only enabled if the window title of the current chrome tab matches to regex - YouTube