SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08161831bc9cd0d668fb855d1989d303a2130dc9e7cfdede89e7da6165dffe4b' 
  AND token = '1aeOI2yhDUOg4kiIMEUKjhrz9HrdNCOLgpotZU7VhdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00065

JSON explain

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