SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2209b3c84d7877a7adb7a6642b6938a055874c4eeea1139b43170f997133164a' 
  AND token = 'FHZSnlpdcA1eBloyYXOykLkJGzBhhKlIaeKOk6Jwbf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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