SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89f31fa1e03b7397404b76a4797c32e4d0f75a3d7d55433ad1f545d75121820d' 
  AND token = 'hlESwVA1zOMv5PH39twCQUm3ou8UZeNEj/JKxlYogBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}