No the word مخلوق isn't present in the Quran as it is basically an adjective meaning "created" and could also appear as a noun meaning "the created المخلوق". But if you are interested in synonyms -which doesn't seem to be the case according to my interpretation of your post- one could try to find some.
In the context of the Quran the only one creating a living creation is Allah that's why it appears apparently always in the form of the verb خَلَقَ ,يَخْلُقُ (in conjugated form, in passive or active voice etc.) and in no verse there's an indication or reference to any other creation as a creation, except when using خَلْقٌ (with the meaning of a new or different creation خَلْقا آخر) or مخلقة (formed) else this creation would be named by name for example: humans, jin etc.
More Arabic words
الخَلْقُ can refer to the creations as used in the linked verse from above (23:14), special structures of the body and its shape, or the act of creating.
الخَالٍقُ refers to the creator and is among the 99 names of Allah, it can also be used for the inventor or maker etc. and it appears in the Quran as a name or attribute of Allah (see for example 6:102, 13:16, 35:3, 39:62, 40:62 and 59:24), not that in (15:28), (38:71) it appears as a verb meaning I'll create!
الخَلَّاقُ is another expression meaning that one who creates (a lot) in Arabic it is an expression of excess. This refers also to Allah as a creator in verses such as (15:86) and (36:81).
Finally there are two words which look like the last one خَلاَقٌ which means share of the good things (often related to religion) which you may find in verses such as (2:102)and (2:200). And the word اخْتِلاَقٌ which is related to fabrication in verse (38:7).
So the use of مَخْلُوق makhlooq for creation and خالِق Khaliq for the Creator is correct in Arabic language, however the word makhlooq is often used in a negative sense, maybe that's why in the Quran it isn't present and the name or kind of the creation is used instead like al-Jinn الجن, al-Ins الإنس or al-Insaan الإنسان etc.
