SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '387a6f7e28ed07c6e1984ed20a3ecad8b44bda24311109af61630a64e496e2ea' 
  AND token = 'hjFnbOXuZ06g0IJ8AGVPl57ugWb17LotVVyOhc2+BE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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