SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a98b46cf43e1ef0f9eea4758b3ba064c1888dd23aaaf9630587e443507234eb' 
  AND token = 'VoX6K3v0CDuXREZzXiU5zg/7ABiSxWXfJIpdlBKK53w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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