SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b1a83fd54fd7e8aba8e9aaac2cea166a45e4e6190ed106e629d59c796ee7cc6' 
  AND token = 'J4K4i328hZOq/iS1EMbeOqkd58qbeGuNmw922K96mRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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