SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ade7aefe7844599016bd1db14a3225438af839f7b96ffedbdacddfdacdbf6120' 
  AND token = 'RINrI9FtEEXaXuQNQo5v2XBzgiRMpZlrEmxExL+8tZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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