SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c300fd80836f3c0e5c0a4262402360b957ef1e0846294d702ff3106758713359' 
  AND token = '7UY8JGFSYBJUG6R3AsHQqef4d+m+Y5OAgfJrPBaYnws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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