SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8546761e902fd0bf936f0e8570602eb76ac9f7a7bbe4ff6230ea27e93911cb28' 
  AND token = 'wxbM6WmkYVWXaHFys2jHh2S16VGdbBkR5YyWMhTg7Bs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00073

JSON explain

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