SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32f6120649e58222cef88710bfb40a00a3bf13278594469e3df0b8be3f964d0f' 
  AND token = 'qYHsn/4ZEicdLf8CDQsem+QH0BiuIUh6qaxUtA+s8rI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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