SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6afc09eccb33d682fb0f3b378b8b4b872225285895d10932eeff12d365aa0863' 
  AND token = 'vMZHtgZFMAuXVnDarJnSqkSbI6jF37ITt+WxXv/Ijhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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