SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffc14c4885b23216772eade10fe9d3b76289ba8bf4a4a9d3b5c3905c3dd9b125' 
  AND token = 'wrdnTew+ozKgg+Bomi89V0nLgprqtzU8xUeGpUF/3S8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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