SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '925b3237dbacabfa95f583fc770d58c23a3405e588ad91d631f79da23fc23833' 
  AND token = '4h113tgv6TozSYgC4zvF8mtwVXhtX1kNh+GI0nQZxpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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