SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7eea14489f675d8cfbe4c5e5ab34ee8982b95bde81087b9addeea8c31d9fbfb1' 
  AND token = 'LM+cAePYePOoKwjwBsVgCHkNCqU71jEwLS2IgB1cY8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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