SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f4841d2ee259a860ed6e25d96a5f393d04690b20e927dba40b65aa5eb129a4d' 
  AND token = 'DShbPhwnQtMY0vk0Vu9Gf0Wwtu+cgSa4ddIT6GiMX2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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