SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '885e7a8b45d79e83d3aea6c1546bca4173996eb6a1cae96640cc368271cbac84' 
  AND token = '6lQrcinZy5j1/OoxmxjwyFGiKDfEZGMoIAIITNeMOKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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