SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49ecf9b7b3fc06da92618e751ee82c5cf6322f837be0970702de7c46e94d5a4d' 
  AND token = 'tSvUfFDD20gtJ9Qpx0S1opHpic+QIYknJsVDgFdtuVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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