Hello RizvanBas, and thanks for your post.
Your decision to be a second-time entrepreneur can certainly be positively viewed by MBA programs, as long as it becomes a compelling and sensible part of your story. I also like the fact that you are making this decision regardless of how schools will think about this decision, because you should always do what is best for your career, and not what you think admissions committees want to see. Fortunately, though, they should view this in a positive way.
You will want to make sure that you can illustrate the value and impact that you have already had on this new start-up, although schools will realize that you just started. Your past work experience will be even more crucial to demonstrate your accomplishments and impact you have made. Ideally this will be supported by strong recommendation letters as well. And in terms of your “story”, it will be important to explain why you want your MBA, and why now. Be sure your story makes sense, and is realistic and specific.
Keep in mind that the application process is truly holistic, and committees will also look at your stats - GPA and GMAT/GRE - and extracurriculars.
I suggest taking an exam up to 3-4 times. You have nothing to lose since schools will only look at your highest score. And even a slight increase can boost your profile. You may still want to illustrate to the schools that you have the academic ability to succeed in the classroom. You could showcase your quant ability in your resume, your recommenders could do the same in their recommendations, or you could even take a supplemental course such as stats or calculus.
Regarding extracurriculars, make sure to really emphasize your leadership roles you have taken on.
Good luck to you!