SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c64b4b76857809ea44290fa686a701a0bde47534cacd1b657b9412fbbcffd2e' 
  AND token = 'agHTXXs769Z/JmNUyzPDI0iO85gUkpu17RPpz6aelD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

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