SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6a72eb742338f79164ef32d0361181e707dcf5d97ea51ab89b104f7f198c3a13' 
  AND token = '1BKFuNCQhZxDIxOPbErRZnFoxpgrmHg3vTXt4xXPlVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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