SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0bc9eb48c3d2067c0c9cb84c037d8d78dbf603fdaec14f1820d858d47ee2178' 
  AND token = 'sH5w7WxonxvgseoWBv7VWducvaTyn+e6gescAeZ2V5s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}