SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dbf4a3496bc06df1054d924495e27fe28d2293415552f053bea6178ac535610' 
  AND token = 'YJSHyU958dMnBzfzYaKi5b0yg4JnHdzqTWP7OstyF/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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