SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b7ee99196b1b72e37152b43cd9a3acb966587e8ceadefede93ca5c5d56cd4b8' 
  AND token = 'S/OzWlDg0+PWspaRxmnxKllolNdBSx/gZwMB411WX/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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