You don't have to install SQL Express to run VQMS. While you cannot use MySQL, you can use any pre-existing MSFT SQL Server database server. Supported versions are listed on page 8 of the install guide:
Microsoft SQL Server 2005 SP1
Microsoft SQL Server 2005 x64
Microsoft SQL Server Express
Microsoft SQL Server Express x64
Microsoft SQL Server 2000 SP4 (installed as
case-insensitive and using the 850 multi-lingual
code page)
NOTE: Mixed Mode Authentication must be enabled, and remote connections using TCP/IP must be enabled