SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a04b8fa9a027e2c4c88cd5add58613570a45af52f96ce683678777ec13fa0f14' 
  AND token = 'PDGdfJ9hkJDocf9XkgWC+j9KUAwi3H2ZxNZpvCI6/4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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