The statement should be such that both the rows- rows A & rows B should be considered of they both have values below 45 and they should be considered if Either row A or row B having values below 45
For better understanding of your problem, Could you provide/Show us with the Input Data, and provide/Show the Corresponding Expected Output data for it?
You could provide Screenshots or provide data in Excel files as well.
The first condition is not required then. All you have to consider is that either a<45 OR b<45. (if one of them is under 45 means that the condition is met)
Therefore your first condition becomes redundant then.