SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '526564844e79a3190bdc5a34a9ba05e8586ef0dde88c936714ee00b668051984' 
  AND token = '5E1/Z8sOK2uOcCfqSv1IjLNVIzXGR4Nr93l5u4WUCKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

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