SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c740f6d7ecfe7ae786cd5dabeb88c4442667641914c360f08c66bbb6a77668b' 
  AND token = 'j1gMPp0YBw+jwexRg3bFS2IbLdMF/XQFQ5/WqLvsYTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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