SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '288952deaa4cddbcb034eb6d94e2cdff1e91b94596072621ba8b2fe3e0bfa90e' 
  AND token = 'JDIVaLWpNKZcIcQywAkzNwZU+9TaICCyKPs4p6+py6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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