SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26a1d6b8cb9f9ab724b5953c51b6847238c764f7200299505a7b726435e57405' 
  AND token = '7kTntlrIZMX51aklqiZxQ5lBON/qHzlKh3MFC+qcpSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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