In second conditionals the past simple is hypothetical, not really time-bound...in some usage grammar books it's called 'unreal past'
Hypothesis or conditionality is not considered time-bound, at least regarding this case. Only first conditionals take the if-clause in present and the second clause in future. The rest of conditional sentences and tenses are bound by aspect (perfection) and unreal reference.
So first part refers to hypothesis, no time...the second tense is subordinated to the first one, it entails future only to the first tense.
The whole patttern looks at the future, as a sequence.
Cheers :)