SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a07f8a33f5955106cd75a588d9222bb793d9b81a92c621c16b91390fb52ee7d2' 
  AND token = '0XZQ+OUn1gJ3nQtomKmsIPYIUhLgwpauL1lCMz9NXRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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