Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '518045d863afb56f12ee0cd05fcbe7f64e6d3f427194bfb3fa6816a118f1fc51' 
  AND token = 'tl5Jp6q+Qiv+YXV+jFgHog40xZZsgLmpoeDb8+Kta5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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