SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46017320ee28382d01e58f7fd16ecf913fe90c36e5c297328f7ecc5c0a68b27d' 
  AND token = 'IyHqs3O/s9Gt7luYwLLofRj+rNeZMjSK2JfBOGLi5ng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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