SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d26399b527150200512db22240c801157fe5ea6f35d91705f9e1369994c7e79' 
  AND token = '3rVKI1oPU9LdHcSuNQV801clNp/BCwDGz+3YDXiO6QA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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