SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f67d4108dbdbc5e3b44280a5e8b8b94a75ef28172e82a750af1c58db575783c1' 
  AND token = '5uGUSzPjTUJ3XX/3dh5x8QfzhYDWTxJUXDz3u1cG6hA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

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