SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '020a04f2bc3c8c433e0407c016080e70f3de892065acf9768bc79674f1d1ffd2' 
  AND token = 'zwd5+JLEdPY+yhJq9oOdsPLAp3LbNbYUmBgu8ppUUW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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