SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d7d3fb616c41a17ef69a8c21210b03abc7fd1d28c40a871954acd33ed264669' 
  AND token = 'NHwQEXH0dQIqG8vWe7kyvnokkDiTdDerscQ3TKrPnlc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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