SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5866826c9d2ebac975eae95ac0964605cd7520de3f0794aaf0ab923d593c5842' 
  AND token = 'wAcLsKJexGanBszoI0AUg30TaADpRWJS4CrM5ZDstvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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