SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7839e8efaa1640301dbcdfe08f070b249235db159ba61b68c6fff1868e3b8ab9' 
  AND token = 'NJNfIphLW8B/rUfHwhCmuddiplk5DWBMWXjUWkIjFAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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