SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc32694d6b999ca34f99b0399dcb7373b8124921a432e657867487063fc4cc2e' 
  AND token = 'REbxwyDAzmiuT7yPQx1OOl6SdaGkIfcbN8KBVCGXuX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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