SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0cf6796f41a64de922bcc942d21d91378feae1a39949ad07b18d3c1f320328ca' 
  AND token = 'Ul+dZemJycYkOyRu53oylqTCcgXNq8OsVIPQGQnlNUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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