SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fb9c6c3f7b30d6882f2ef7036426a9d4b6cd46c9632acae11b5f64758f4f209' 
  AND token = 'JCqPlf/+mV/iSN6oFRn02BkS02WoJ54R1oJEUOAEWK4=' 
  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