Yes, there can be case of 498a even after seven years of marriage.
Section 498a IPC (Indian penal code) provides for the offence of cruelty committed against wife by the husband and his relatives.
Section 498A IPC. Husband or relative of husband of a woman subjecting her to cruelty.—Whoever, being the husband or the relative of the husband of a woman, subjects such woman to cruelty shall be punished with imprisonment for a term which may extend to three years and shall also be liable to fine. Explanation.—For the purpose of this section, “cruelty” means—
a) any wilful conduct which is of such a nature as is likely to drive the woman to commit suicide or to cause grave injury or danger to life, limb or health (whether mental or physical) of the woman; or
b) harassment of the woman where such harassment is with a view to coercing her or any person related to her to meet any unlawful demand for any property or valuable security or is on account of failure by her or any person related to her to meet such demand.
As per section 498a IPC the punishment for committing the offence of cruelty may be an imprisonment which may extend to three years and fine.
At the same time section 468 CrPC (Criminal procedure Code) provides for a limitation of three years from the last incident of commission of offence by the husband and his relative.
That does not mean that a complaint can be filed a any point of time by the wife or her family members, if there are no incidents of offence in past three years then the complaint would not be maintainable unless the delay is condoned by the court.