SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0efef4d099f8720d8ead66b5631f393d8e18c21b17b05ce58b325e2a84ffc3e4' 
  AND token = 'EghVtEcyS+7UPjDt59zvAKyCIJT0EzVZ+Mzj1jZC/pU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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