VLOOKUP by Combining 2 Columns to Form a Unique Key

You can use an array formula:

=INDEX($C$1:$C$7,MATCH("1foo",$A$1:$A$7 & $B$1:$B$7,0))

just select in example D1, enter formula in formula bar and press CTRL+SHIFT+ENTER to evaluate it

The way I usually do it is by concatenating the values separated by a pipe character (|). See the formula in the screenshot below.

=A1&"|"&B1

Then you can vlookup using the concatenated key.

=VLOOKUP("1|foo",$C$1:$D$7,2,FALSE)

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