SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'beb6ac4e69a230c61bf4b23ceb4b5bc72a8072ad06866a00fb77483a39e16d2d' 
  AND token = 'er5Tp1clZLiraSufxXL+UrHngnzBHeJ7EzorGGdMB5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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