SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6abe8d34577b34d54816827af3d67d190e9ad7595e14ed3c4f087387ea3715b' 
  AND token = 'Yt6yLoHpxzIzo0BFnUsSi8tuGd3HArJZbbRmbyCQoEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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