SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '347127a013e42507e84048fb7c674699fe1efe9f9506cabf85e4e4a5ea4120fc' 
  AND token = 'KtBaoNywDzhnmG7uEol+CQv5rz1BHlK3sqV3baQZxyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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