SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c4f813dc37576fddcffb1e37b13cf8e6a97822f102bdbff91085ba910d48029' 
  AND token = 'vAw8cc2ImvPk8LEX1NrPA5ZaPlCMTl0J4req3MThQZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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