SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '643370f1f9a32d56ca1138c790db4f626a87dd05ce4dc6f860ed81251c2688cc' 
  AND token = 'o8oMyJIQyaFJZ0hOksCTx9LmXrSe4OP/ZTGhwUdHdPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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