SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43eb67d152b00b2bce842e7c886d3bbbe99c31e2f1b6eb1ce92652f904c38419' 
  AND token = 'MDwnEwDx9ZJVrd1S92HmMVyNPgdUR8+Sy3HBiX1UiOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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