SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '08125a08cfc691dc0edbbae66d8043d54068276e5fb97c7f5c23b0d6b07fed47' 
  AND token = '8Win7azcUjfCWsRjnzErXbErPkd2xajluXZGMtwgJPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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