SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79cb58c1fc3f288f0d7d02dbd42f94c828c393e680a7a619fe9837883a356ac2' 
  AND token = 'ETXWVIJl9/G5tPK8x7nijhQ/gUORhGIF4evBEujDH5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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