SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bf6407a22bc7e1140144754a689a61687f76f5c48ec3973731d7a60e68b52509' 
  AND token = '4NdXd8JsNqCwl5NaJZ6lJSvTiBz/u4LQj/1AZntiZrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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