Hi Patryk,
On the Frontend Search Settings -> General panel you can enable the “Show exact matches only” option: http://i.imgur.com/6zMBR46.png
Exact matching is still a substring matching, however the string must match as it is, including the ordering.
Exact matching with word boundaries is not possible without using regular expressions (using the RLIKE operator) in mySQL, which is extremely inefficient and resource heavy, it’s not implemented for safety reasons.