SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c752c00d735991f42a4b828e7901df3af24e21be38b6843fdc114f344aa881ae' 
  AND token = 'Xzzv8a92FoNhUPPXolHPwtFqE8LsdFtnAGpg5GuBwlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables