SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc3240b2feea8820f9da5a27e0dc87bba1a5bc7ab1cc1999b3535528440aad64' 
  AND token = 'Blv8289xV2tWQK/x9/0n4Qbo6F33d0OjdvPO+gOlH4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

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