SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0a873f590403ebaf4e99c206afc3f9e76235123f05db9b7dac9c7bb58592b5e' 
  AND token = 'UO6AXq8+fFndvuAY2OQNBjdOmaZVd9qbWm464TJJ9tg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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