SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cb3489e3b15d151b70f0a1928560420c0fbd6d91c40303aac117c74f4cb052b7' 
  AND token = 'DPbbUX3QZKljCo9wEDoUhrQRBIOfp4I9cxu+qhzLdfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}