SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19429d9dcceb7ad03f1521912107ef07b4fa52315494a10bfc2941815ec2b6ac' 
  AND token = 'rmInxhmo2hjWkFlVjxiAoM8AqRO1qDUGt4azGG81Vi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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