SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '584af1989eda54465cd306a06502131a821ee3b41821ea14cc022024bd4faa91' 
  AND token = 'ky8cz1XYP4E0oPAnwHqe0TSBFIzoV4rq4BnaI5purLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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