That's not really an age gap. I wouldn't consider anything of 8 years difference or less to be even noteworthy unless one of the couple is under 21.
IMO two people of differing ages with similar goals, values and attitudes in life will always get along better than two people the same age who are vastly different in terms of goals, values and attitudes.
However, the thing about age gaps is that it is largely down to perceptions. If you feel it is too big you will start looking for evidence that it is. It becomes self defining. And if you are the sort of person who cares what others think, an age gap can become blown out of all proportion in your head and ruin the relationship anyway. Large age-gaps require something of a thick skin, no matter how wonderful the relationship between the two people concerned.
Practically speaking, there are considerations that apply if one partner is very young or very old. As a gross generalisation, it is rare for someone under 21 to have a successful relationship with a 40-year-old that lasts (particularly if the younger of the two is male), which is presumably due to the lack of life experience in common. But there are enough exceptions to that for it to be obvious that this is a generalisation, not a truism.
At the other end of the scale, a young, active 50-year-old married to a 70-year-old may find themselves faced with a situation that feels like looking after an elderly parent. However, if the relationship is otherwise healthy and the couple love each other, they will weather that, just as two people the same age will weather a chronic illness or redundancy, etc.
It can also cause problems associated with fertility, but again a healthy relationship will deal (or not) with that in the same way as a same-age couple with fertility problems.
But at 37 and 45 I'd say just go for it.