SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'bf8684ed20fb77f88357f5575335f280795441978647b540e41a9e6924838f06' 
  AND token = '5B9OZeCq5HZmxFdA3ZYI+K15RK0+l89zCE2DWBdnW8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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