SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8bd2a1a0f63e9f24ffe0be6fd6fe1b87a2eb6970696376298a13e0a8e35fd0d' 
  AND token = 'NBrUUqaSSZvE7m4burwSO13H9zfUp+4Leee1nsj+qbQ=' 
  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