You are using the old IF ERRORLEVEL syntax from MS-DOS.
IF ERRORLEVEL N do_something means "If errorlevel is greater than or equal to N do_something"
Since ERRORLEVEL will always be greater than or equal to 0, you will always get the "found" message even when FIND returns a nonzero error.
What you want is the Windows NT modern version where errorlevel is a proper variable.
IF %errorlevel% equ 0 do_something
However you are in a loop so you need delayed expansion and you use ! instead of % around errorlevel
IF !errorlevel! equ 0 do_something
so try this
for /F "tokens=*" %%f in (toFind.txt) do (
find /c "%%f" 1.txt
if !errorlevel! equ 0 (
echo %%f "--->" found
) else (
echo %%f "--->" not found!