SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'efa9977e91c5a2efa48b8bdecf86631076fdb4aa0db0265ebec7eb6ecce10b9f' 
  AND token = 'RxrpYbayeDHr+1qBYIih44nVRBegSGLHgzj3ZXIC6hk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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