$ sudo yum update
(中略)
warning: /var/cache/yum/x86_64/2/mysql57-community/packages/mysql-community-libs-5.7.37-1.el7.x86_64.rpm: Header V4 RSA/SHA256 Signature, key ID 3a79bd29: NOKEY
file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql から鍵を取得中です。
The GPG keys listed for the "MySQL 5.7 Community Server" repository are already installed but they are not correct for this package.
Check that the correct key URLs are configured for this repository.
Failing package is: mysql-community-libs-5.7.37-1.el7.x86_64
GPG Keys are configured as: file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql