SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb6fe75950d814b4477ccdcf22f6c212bb1917473f51cb21910328a4b3e42241' 
  AND token = 'Ww/F2c1kO8C9h7jKOq1r78NryD39KPSA/xA8fsLdtDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

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