SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '313442ccc6dfefb5ea503a759f03767796f63e3b2d8cfe78be8b1b11e205b3d8' 
  AND token = 'ltQJRI1vrQtJOaZhEINfxwlU/Y/xLs2Z45uhGF2c6BY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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