SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '925fa46f3f055437eda0a50c341582a1de603a6f0c13d9ddfede235bbc420531' 
  AND token = 'AB78kcFgz2FGoJEjifDWmjwuUD9D0cKITVitUrBx4W8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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