SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6aaa7431408d52194f3b491baafafc55c63bb6c4cb0228cbc284c10082387b40' 
  AND token = 'Z+iPt8XXh2HMPTgu9QA8dsuAAABHKAzKVCReLpXpYE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}