SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c11a8c609460eed29b726563cea23d49dbc78f546f94734b445fc8ec9a4c991' 
  AND token = 'Z8A8SYVigdSp2Xmqrfcr30wg1fQJhcfllkRsqXrKsPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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