Hi there,
Congrats on the stellar GMAT score! The GPA is low, yes, but the GMAT will help to a certain degree. The top 5-8 schools may still be a bit challenging to gain acceptance, but beyond that with strong essays and a great explanation of who you are, why b-school, what your goals are, and why that program is for you.... you could still have a shot.
The schools will look at your entire profile. They will also consider-- where did you go to undergrad? What was your major and what courses did you struggle in? How have you demonstrated leadership? Quantitative & analytical skills? Communication skills? Teamwork? Going above and beyond what was expected of you? Why do you want the MBA? What are your goals? And so forth. So those essays can make a real impact as they assess the whole picture of your profile and application.
3 years upon entering is slightly less than average (average student has 5 years); not a huge issue but you will want to be sure you address why NOW, at this point in your career, is the ideal time for you for b-school.
All of the start up and business development experience will be a plus though, so be sure you speak to that and think of how you'll bring a lot to the classroom based on those experiences.
Let us know what other questions you have, and good luck!