SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20d3b347118c347c0f0005f1c4aefd6340e9ff25d80bea7559d356e86e51ab68' 
  AND token = 'zcs/+remyigBHukxJsWIcyUFQHHU9OJyAkQsiuEvtdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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