SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e1fd99adb7e494d451afcbb977a87cf998e92699aa96cfaa115cdb134a7dc31f' 
  AND token = '78cJ/A2o0abyUmRePJFiaCUo9eKfBgtgx6scaDnwg8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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