SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '320654428e7d617d8b7e26aceb9c6d584832da5da087566d1d358349497d8c3d' 
  AND token = 'zyUi0aRxbpj8sjFsoQcilSO0D4kBv8sfDnHYhlqNgZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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