SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b0df1d6cadbbd67ede2b6e8909c9e53f3a7053c60e79d3472a75efce5f3da87' 
  AND token = 'QGR8K9VVdtwK2XueuKGcZ/P4W9awiCi/ILwDp3RC1lE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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