SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08dd4f09df30107d284bb9384bf95228ff2fe0fc05d7e08a7e6dcc85056f6a90' 
  AND token = 'PpSe6V9vdCf/xRQYWVyhXj4Ipl/ukC8Ji4IgZMQZb1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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