SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f5d0bebf9cf49462a9c76adce2f4cf15f1905a12b16779da58cd9ba8b5dae73' 
  AND token = 'pFuwoXk6q5qwM1+1n8vigwZN8vZk0hLepZEI1KUHMQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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