SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f4233dfad51bbffd37932e5fdd7fdca425588bb805d0bc636ed343d9429c9a7' 
  AND token = 'FFE/Wh5XSD5PzIGVBrjgdUnCDV9dNVvy8Mu91UDrQLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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