SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36a80497beb0c6b6ffea5f28ea6992238d3ca61f6ffce3e27e237adf07c4d26a' 
  AND token = 'vfdDttvoQfnNMnbvxQeTtA5vGXz+wjgF4A9//n4HY8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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