Subtitle Cinderella.2015.720p.bluray.x264-spark... | Premium

If you are looking for a "useful piece" (the subtitle file itself), this specific release is highly standardized.

Rename the .srt file to match the .mkv or .mp4 name exactly. subtitle Cinderella.2015.720p.BluRay.x264-SPARK...

If the text is slightly off, use the G (delay) or H (speed up) keys in VLC. If you are looking for a "useful piece"