If your SAT score is below 1300, it could hurt depending on the firm. I would strongly recommend against retaking the SAT. There are better uses of your time. However, if you believe you can take it right now with no practice and score a 1500, no one will stop you.
If you have a low SAT, focus on the areas where you can make a difference – a great GPA will go a long way. Shoot for leadership positions in school, gain part-time work experience during school and recruit for quality firms over summer and post-college.
Same applies to GMAT – 700 is your cutoff level there.