How to find a DIP component implementing this simple logic?
That's a 1-to-2 demultiplexer, where the lower input is the select line. You can use a 74HC237 3-to-8 demultiplexer for this. (They don't make the smaller versions like 1-to-2 in DIL package).  

Use A0 and A1 for inputs, and Y1 and Y3 for outputs. Make LE, E1 and A2 low, E2 high. Then you have the following truth table:  

A1  A0    Y1  Y3

 0   0     0   0
 0   1     1   0
 1   0     0   0
 1   1     0   1


So A0 is your data input, A1 is the output selector: low selects Y1, high selects Y3.  

You can use other input-output combinations for the same IC to achieve this, or for instance use Y0 and Y2 instead of Y1 and Y3 to get inverted outputs when selected. This is the full truth table from the datasheet: