SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d8c65425c3bda7285a0bd9b80632262bad2cb2190dc596c3006042e2c842913' 
  AND token = 'nISn9sV6UJfhMV/LlyOHhRJhI6YnlzhyAzxoChKg3bg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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