MySQL:resultados coincidentes y no coincidentes en la consulta Where IN

Puedes probar a continuación - usando cte

with cte1 as 
(
select 'abc' as key
union 
select 'pqr' union select 'xyz' 
)
select keyword,case when key is null then 0 else 1 end as is_present 
from keywords left join cte1 on keyword=key