No, there is no such product.
"Value" is a historical construct; it only exists where products are made to be sold as commodities. When there was no production of commodities, products had no value. If we reshape our societies so that we no longer produce things as commodities, there will no longer be value.
Even as long as products are commodities, their value necessarily changes. In Marxist terms, productivity of labour changes (increasing in the long term, with technological progress, but flutuating on the short term), so the labour time necessary to produce any given commodity isn't fixed, and neither is value. In neoclassic terms, the utility of products necessarily changes with technological progress: things that were useful become obsolete and lose value, things that had no use become important for new productive processes, and acquire value.
Of course, the value of some commodities is more stable than the value of others. Gold has always been very expensive, while aluminium was very expensive but become very cheap due to new productive processes. It is reasonable to believe that gold, as long as it has any use value, will always be expensive: there are limited reserves of gold, and gold cannot be created by transformative processes. But even here, fluctuation is the norm: gold became much cheaper, though still very expensive, in the 16th century, due to New World mines.
In short, you won't find any product that has had a stable value since the inception of commodity production. And we won't be able to make accurate predicions of the future value of any commodity, because technological progress is unpredictable - even if we assume that commodity production will be the form of economical activity until the end of times - which is far from given.