SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac5e162973678d81b64550213c37c8cfda0b0fcdd44c9edad7eccff2ddf66fb4' 
  AND token = 'IDnHOYTD72K5/MlrfuArq/GvFz7iWt3+tdAMbQcoIdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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