SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a39bc40eab8687748d0e180a78f7ca3d162417d05551497fb7d5bb0c1097843' 
  AND token = 'WdwE2lMPArW++JISfWWKY4A5aJrOV2kkbUjeeGsX06w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

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