SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '551fa69f1c87d16e4ee9d231c84935f4b7f31564b801f69c0386c0cb3999f34a' 
  AND token = '8VGggUYwVEkEELxeMNv4+LnhfIvLcXTpsipaYXNrq+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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