SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30d0ee9d184aab12210821114565998f43527674785a3b9d47c605cfa9d82580' 
  AND token = '5xAOjPpkM2mWSl6lLKsyOFGIUJ+DXhZJLkdM78+Vdss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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