SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55323ec2794fddc962ba859a23ee8a204640b19f644a480fba5f420207a5fb7f' 
  AND token = 'UOGuZuJsYEpOH8wfs6/qdGd7X90sS8bm+dnSrNOoSmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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