A quick note to advise that SQL Server 2012 Standard Edition does not require the start-up trace flag 845 in order to use locked pages in memory.
You do however need to ensure that the SQL Server service account has the ‘Lock pages in memory’ privilege.
The ‘Lock pages in memory’ privilege can be set via:
gpedit.msc -> Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> User Rights Assignment
As per best practice, ensure your SQL Server has Minimum and Maximum memory thresholds configured, with enough memory left for non SQL operations.
For further reading see How to enable the “locked pages” feature in SQL Server 2012