SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7635debc2b60b9edaa578a88be00994ddcb4675da385eaac1d8ea6652af9b702' 
  AND token = 'caxNePiVvDK8Cz1YDkluV/rlGNzYKR+t7Lg0h0UnZ5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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