SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50bb5be6ffe2eb3569528ad1d12ca5f2ac9a20a96bc07efbfca41c2363a490be' 
  AND token = 'ez467wm+BwyLyh6GpZ21xJMgfHGyJCY+3bgLenCdjvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

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