SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ce67ca8a9f0e7f921b0e23a92cf1aeff54da344aca8f331ac7a0da1234b98b64' 
  AND token = '9K7XFiRkoWrV8aa3wkBosAczZFD9mEC45Sj1RwKWpTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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