SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ae7d9ee75583a6cbb829181fe2b0793ed2004f40dd058e4050d88d3f57b253a' 
  AND token = '4mxYDBqf9ZykjPtK2eDZhgSRmkxe1TZIHL/K8vxbS0g=' 
  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