SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8360628787445049dc8186f2f653d759dbc2e6e4f80f4caaa86bc6eccbf067c8' 
  AND token = 'Y4ePxSiUKgynovFeoDvGANEJoz+ur0FExVfIFgIUhp8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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