SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1caf59a64e65989fa6662b77125d41a50bc1ecdf1200d534d0921ea2f017e28c' 
  AND token = 'qY+Orv6QNP5cjm8aFchn2ob+UehOdG3nAUvb5dkcyVo=' 
  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"
    }
  }
}