SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de2709d3e05c9fc1c85214fd0dabc16bc18ce8eaa0100bb5be406b591a1ba5a3' 
  AND token = 'tZlg8u1dVEXto/jtxBVEhXbTrizkpYkZxds97DQBnCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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