SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '294ffadf6cc73dcdc57dda5315cde38a4d43221cfdc2620e4ef747f88b92df23' 
  AND token = 'J13TZWvMEKkQLpyf3PXwSQiNKZlBwS5EuZc2hfZ1Ba0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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