If you want to extract the files to the respective folder you can try this
find . -name "*.zip" | while read filename; do unzip -o -d "`dirname "$filename"`" "$filename"; done;
A multi-processed version for systems that can handle high I/O:
find . -name "*.zip" | xargs -P 5 -I fileName sh -c 'unzip -o -d "$(dirname "fileName")/$(basename -s .zip "fileName")" "fileName"'