Use backtic and not single quote for movie-name and key and remove alias for status (because this could create problem in where)
$sql3 = "SELECT DISTINCT id ,status ,`movie-name` as `key`,
moviename as value,poster as cover
FROM movie
WHERE id='$movieid'
AND status='Coming Soon'
ORDER BY id DESC
LIMIT 6";
if movie-name is a name and not a column use single quote for select the literal value but remember of don't use improper alias like status in where condition
$sql3 = "SELECT DISTINCT id ,status ,'movie-name' as `key`,
moviename as value,poster as cover
FROM movie
WHERE id='$movieid'
AND status='Coming Soon'
ORDER BY id DESC
LIMIT 6";