singning key of repo expired

Hello,

i get a key-expired message when i try to update my repository

root at merlot:/etc/apt/sources.list.d# cat rbase-stable.list
deb http://ftp.gwdg.de/pub/misc/cran/bin/linux/debian buster-cran40/


W: GPG-Fehler: http://ftp.gwdg.de/pub/misc/cran/bin/linux/debian 
buster-cran40/ InRelease: Die folgenden Signaturen waren ung?ltig: 
EXPKEYSIG FCAE2A0E115C3D8A Johannes Ranke (Wissenschaftlicher Berater) 
<johannes.ranke at jrwb.de>

As you can see on

https://keyserver.ubuntu.com/pks/lookup?search=0xE19F5F87128899B192B1A2C2AD5F960A256A04AF&fingerprint=on&op=index

there are two Expired Sub-Keys:

sub rsa3072/5bc121cfdc61bdae03062260af83ce117fbb4c22 
2016-11-15T20:12:04Z
sig sbind ad5f960a256a04af 2016-11-15T20:12:04Z ____________________ 
2021-11-14T18:17:46Z []

sub rsa3072/ad7b5162ba456be3526f8d92fcae2a0e115c3d8a 
2016-11-15T19:58:24Z
sig sbind ad5f960a256a04af 2016-11-15T19:58:24Z ____________________ 
2021-11-14T18:17:46Z []


greetings, bodo

R.-Bodo Riediger-Klaus     IT-Dienst FB MI Freie Universit?t Berlin
bodo.riediger-klaus at fu-berlin.de Takustr.9 R.038 Fon: 030 838 75175