SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b1fabcff8a9c1bf61a5904c12efa8992d8cf69f279c11ffa59cdb60e64836fe1' 
  AND token = '+ajLBYRlBgPPSxXaHTXigAsXh82MBjLMgTkUQKRIAeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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