SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ada98f1ca580c566fe00cfda409857f563c7aff85144b7c7fc92ff76aa042c50' 
  AND token = 'WpFTemitDrObNiLdaugoBJrJ/amH61URAvQkG276FZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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