SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89a9814319762a15df132e1811988e444fb598fe182787a53563d5425f96d41b' 
  AND token = 'YE8mglokNRzGOZVLCm95W4H0kYrW3nwDjUl6gMPxvJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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