Did not take note of my indices (barcodes); is my library salvageable?

Hi everyone. I have a rather annoying problem:

I planned to sequence two small RNA libraries I created a few months ago.

I neglected to write down the indices that I used to create these libraries, and now I am at a loss as to how to continue. Is it possible to perform PCR to detect my barcodes? Can I run these libraries without knowing what the barcodes are right now, and demultiplex later? Or do I need to start over?