SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d1928cc5ff141d29dcde05cc969bfe7a0807c1f3fb16b4efc68af86005cb5e9' 
  AND token = 'I8030nux4/+PgCszzYLDRmQPdN02lavu36vw0iuOEXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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