SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80abfa3e3faffd57c7c2f6b078a171b426eeb157f7904fbc847f5fda3ff992a9' 
  AND token = 's+mdOaiVK/aYkXpsYTUJIgqysWN0nj8jCda4qlXQTuc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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