apt-key expired for deb.sury.org

Today I had the case that the following message suddenly appeared during an update:

The following signatures were invalid: EXPKEYSIG B188E2B695BD4743 DEB.SURY.ORG Automatic Signing Key

this was the solution,

1) delete old key:

# apt-key del B188E2B695BD4743

2) import new key:

# curl -sSL -o /etc/apt/trusted.gpg.d/php.gpg https://packages.sury.org/php/apt.gpg

3) update package list:

# apt update

The error should be fixed.

Thanks to https://www.myprohost.com/en/blog/apt-key-expired-debsuryorg