SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9af0ee138c47f4f2c970b4741164a7aeeda3e7d07542aaa8fc7a3ecd43d43917' 
  AND token = 'MHqylKKgAmeTmnZcUPa5DxEKL8fh8U0nGNOfxQXI3Jg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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