Hi,
Exact matching within the file contents is not possible. The files contents are parsed and stored in the index using the index table engine. With that however there is no way to have exact content matches as that information is lost during the indexing process.
You can do exact matching when not using the index table engine, but in that case searching the file contents is not possible as those are within the index.
If you have a lot of content, I rather recommend using a more strict keyword logic: https://i.imgur.com/Ki28fGX.png