SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e14fae7e21e6fd9ad56649d60cd94fdf9966abe47dcf15d8b3de43952405a804' 
  AND token = 'cbot/mPBdm7kTT17FptW/n3Kr2Y5KzQP7GWFwlKxcPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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