SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c30621083a21a2472b81f9f516c9c0c12900de3cc219e287f7af97283886cb07' 
  AND token = 'OZp6Bnktv4H2gUs5dfGoGWBHvVI2zZZAkq3xDzQ3a+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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