You may introduce a formula like the one below in a new column.
X3=AND(A3=A2,B3=B2)
Copy the formula to all rows. This is to be applied if your data is sorted
one. Assuming the formula is applied in Cell X3. If returns TRUE it means,
row 2 and row 3 are duplicates. If returns false, it is not duplicate.
Delete all the rows containing true value.