SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99a63a9df4df88479a1185bbd657404455f93eaf8fe0f74b754e4cd02770e959' 
  AND token = 'K/MBNAZwsuaHf/axp73ENg3ifwkiTYvCqqXhd++bZjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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