I am sorry, you are right. We also append some other numbers to that string to obtain an unique md5 in case you change the seek granularity.
In your case, the md5-ed string would be:
MD5 ("D:movieGirls_Generation_I_GOT_A_BOY_Music_Video.mp4_1_100") = 5218bf1119c9fac5577672958f303591
first number (1) is the keyFrameSeek setting. Second number (100) is the seekGranularity (100 milliseconds)
Those were factored in because we need to regenerate the *.seek file if that changes