ok fastest way.. it depends.
IF you had for example 2 special folders you sometimes want to search, then add those 2 folders to the SearchFolders tab and add a keyword modifer to them.
Then if you want to search these two folders you can type for example
+mydata test
to search those directories for files named "test"
If there are not too many matching directories you could just type a couple of letters of each.
So to search in "c:\program files\my database\backup\config"
you could type:
"c:\pr\data\b\c"
Just remember that when you dont use explicit directories then FARR has to search more to make sure there arent other matches. so in your case you could also do "C:\downloads\settings\" and it WILL find "c:\downloads\apps\config\settings" if there is no exact match for "C:\downloads\settings\", but it may take a bit longer.
Yet another option is to use the Tab key (or alt+# on directory names) to autocomplete each directory as you type it, so that you type:
C:\pro[TAB]my[TAB]b[TAB]co]TAB
and then see in your search box "c:\program files\my database\backup\config"