Try to change httpd.conf to this one:

# The ServerName directive sets the request scheme, hostname and port that
# the server uses to identify itself. This is used when creating
# redirection URLs. In the context of virtual hosts, the ServerName
# specifies what hostname must appear in the request's Host: header to
# match this virtual host. For the default virtual host (this file) this
# value is not decisive as it is used as a last resort host regardless.
# However, you must set it for any further virtual host explicitly.
#ServerName www.example.com

ServerName 127.0.0.1:80

if that solution doesn't work try to change database configuration from localhost to 127.0.0.1 After that, to make sure all thing will run well, restart the apache first.

The problem is with php artisan serve. Apache is perfect.