[*Caro*]

Hola, te quedaría así:

Código SQL [-]
Select sum(cantidad)
From (SELECT DISTINCT (lsd_checklist_id), lsd_checklisttranslations.`en-US` , COUNT(lsd_checklist_id) AS cantidad
        FROM lsd_decisions 
        INNER JOIN lsd_checklists ON ((lsd_decisions.lsd_checklist_id)=( lsd_checklists.id))
        INNER JOIN lsd_checklisttranslations ON ((  lsd_checklists.key)=( lsd_checklisttranslations.key))
        GROUP BY (lsd_checklist_id)
        LIMIT 10) T1

Saluditos