uftaadah : 'Fallen, lying flat or horizontally; lying waste or untilled (land); poor, wretched, helpless'. (Platts p.61)
qanaa((at : 'Content, contentment; resignation; tranquillity; — abstinence; ability to do without'. (Platts p.795)
That is, who in wretchedness and helplessness would remain content. Through calling the footprint of an ant the throne of Solomon he means to exaggerate fallenness and loftiness of courage.
The footprint of an ant is very small and humble; then, it is related to the ground. The time of that weak and insignificant one is happy, who would content himself with dust-sitting and would consider it to be kingship. The footprint of an ant and the throne of Solomon are two limits of worthlessness and grandeur.
For background see S. R. Faruqi's choices. This verse is NOT one of his choices; largely for completeness, I have added it myself. For more on Ghalib's unpublished verses, see the discussion in {4,8x}.
This verse belongs to the set of 'independence' verses (for more on these see {9,1}) in which Ghalib suggests that it's desirable to rely only on one's own resources, even if these are inferior, rather than borrowing from someone else. Here, the 'fallen' one who is content to stay down on the ground is not only is a credit to his age-- rendering it 'happy' in the sense of 'fortunate, auspicious'-- but also has an extraordinary kind of potency. After all, the second line tells us clearly that he would 'make the footprint of an ant into the throne of Solomon'. And what could be a greater sign of independent, personal power than that?
Asi:
vaqt us uftaadah kaa ;xvush -- it is the translation of a Persian idiom. As Urfi says in a verse, vaqt-e ((urfii ;xvush .... In Urdu, we will say, 'Oh Asad, that person is very good who would, through contentment, stay settled in one place, and would consider the footprint of an ant to be the throne of Solomon. He has said 'footprint of an ant' because of its being 'fallen' on the earth.
== Asi, pp. 234-235