Thank you for your answer, @UFHH01,
pdo_mysql was missing in my version of /usr/local/psa/admin/conf/php.ini configuration file.
I have found it using command
# ps ax | grep mysql.sock | grep -v grep
17374 pts/11 Sl 2:55 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql...