SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60b8dbda152384775a773fead8ecaba2fec7a1c93bbe22d463ce36e28bad138f' 
  AND token = 'WYmVJgB2/XfUjiqTkmt6AL6mtjSkKNWf/Vytgvm1ttw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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