Ssl – Apache2 not asking for password of private SSL key

I am trying to set up SSH for my apache2 server. Apache seems to find my private key, because it complains once I move it. But it doesn't check the content of the file: When I replace it with gibberish, it will still give me a nice startup

ks@survey:/etc/apache2/ssl.key$ sudo service apache2 restart
[ ok ] Restarting web server: apache2 ... waiting .

Shouldn't it be checking the content of the key file and asking me for my password?
Here is what my error.log says:

[Wed Jul 23 22:21:55 2014] [notice] caught SIGTERM, shutting down
[Wed Jul 23 22:21:56 2014] [notice] Apache/2.2.22 (Debian) mod_ssl/2.2.22 OpenSSL/1.0.1e mod_wsgi/3.3 Python/2.7.3 configured -- resuming normal operations

(My version of openssl is supposed to be patched and free of heartbleed.)

Apachectl gives the following output:

ks@survey:/etc/init.d$ sudo  /usr/sbin/apachectl -S
VirtualHost configuration:
wildcard NameVirtualHosts and _default_ servers:
_default_:443          survey.zqa.tu-dresden.de (/etc/apache2/sites-enabled/workload-ssl:2)
*:80                   is a NameVirtualHost
         default server survey.zqa.tu-dresden.de (/etc/apache2/sites-enabled/workload:1)
         port 80 namevhost survey.zqa.tu-dresden.de (/etc/apache2/sites-enabled/workload:1)
Syntax OK