SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6389690324887214f62e17f7a431e8bdf1b7852b10461ae1ebc414a170c421e3' 
  AND token = 'Uo/usdCSvr5GBlaX39rc9cWwMcJMIJmOBbeP4Eiuh64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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