SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25f30f7954a0e1e7b0bc2f30416279129c7aa8f611a65db4a6a197c04831be3e' 
  AND token = '/VYwVbv6Koagj05s29OPzWU+ZPrSn9BRMgu4KC8a8HY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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