SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e3ca7ffa34716e78f0ac8cdc08dfdad506658ce50db53b79021e7d1af3e08bb4' 
  AND token = 'eBx3DYNKZxeGbPjxSSpwg8fIUF7qLmJ0TMNSfKqGOzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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