SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebc3428ea8bd624b7bb1d4f048e197a49f2ff3d8390c70be1906d56a7e4e00f2' 
  AND token = 'DGdDZMBCLBizYolVtU5oe155qGXX5+VQKTjS9z0ZSSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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