SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bdd40a698679d5e6755fc85046d75b2251d968b7d7c33ba0ee3a8670da4914b' 
  AND token = '+XZV/BSHySXpohvDhbw+fZ3UdX/ZrFCJoi9J/6Ddwlw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}