SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7452a08194a45746ea38ca43e5cf23556381bfe0742b8bd209c17fdece28cb1' 
  AND token = 'rjh/AuZIxmzzU7yAhQn6/1FLcSO1ZwfKi+5bJZ2OrQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}