SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4045a6098be46ed6072f2815ae0a47918c5e775eaea84dba69e98fbe71393de5' 
  AND token = 'fRpgBn45GclxuWQhGRYlJFCD/sR4GLti9PIJ7b1ziPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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