SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '004d43dc06d9b3dfa673294a233dfdcd20f05013799e0f8f3e8aefcd01481f3d' 
  AND token = 'D+9qUAgscShK1c1uOZT1Wy/b1R+Yx/sMKs0f4RXSD7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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