SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0b8d98bbaaca77e1aacb4775de518e4d83f165f294980bf2cb3ca5d859cfb212' 
  AND token = 'llfkYnK3OTBPy++tDrF8sJHfUWS4I0sBVloOorRg4Js=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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