SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70b2de4dfe6bf2698acf25b57c6d7ab11db8757d76a79cbf85c3449ea6e4a834' 
  AND token = 'lKltYB+MqY7U8D8k1lfiMXQSoZb0XX21GdL1Z1kx6pQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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