SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17b4916183d1d37d6ee437f14600a524d537623135152f148381a38f786c06e3' 
  AND token = 'LTGgtp7nhTccC39bBXctRMKP0OYoGu5Mnc5hts4xZNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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