BitFarmer

You just need to create an index in the database using this row (don't know how to do it in Access, but should be difficult), so, looking for a particular value can drop from 30s to may be 0.01s

If this column value is unique among lines (not 2 lines have the same value), then you can add the UNIQUE flag when creating the index, it will make it even faster and avoid adding a second line qith a used value.