SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edc0ecf0caec76b4903386234c259289378a6714d5f6dd18266783f0d45bbb65' 
  AND token = '0YXdBteV9PC58y/LwYb+ogaZmGiZMz8qB26op/hcVFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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