I do not think that is accurate, and I’ve never heard of a saint saying this. The sinners who seem happy are thus because they take pleasure in their vices, refusing to believe in the punishment that awaits them which will subsume all their illicit pleasures. It is written, “People say, ‘Peace and safety,’ then suddenly destruction comes upon them.” Their sudden destruction comes not because they weren’t warned, but because they refused to heed the warning.
Even so, we despair of no one’s salvation: Remember how Manasseh of Judah repented after being taken captive, and how Nebuchadnezzer of Babylon glorified the God of Heaven after he had been mad for seven years, behaving as a beast. Their arrogance was great in the days of their sinfulness, and doubtless they seemed happy as they dwelt in their palaces, showing no regard for their Creator. Who would have suspected either of them to repent? Yet their repentance is Scripture! The fool rejoices in his wickedness because he imagines himself safe, but when convinced of the wrath that awaits him, he trembles, and the fear of God is the beginning of wisdom.