SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfdc59b4748df4e760db3192b44fed23ed8ae2e4203c7a889d58dd201bb615b0' 
  AND token = 'PK1WLBw1DaY/QUePG9ViT+XqP08JJ6K9h4KX+vwOXLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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