SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1e92c2900a930b7bcf28b1e471db3353bb6382b6a69dff43f95bbd85edb524c' 
  AND token = 'MmB/jZ2GwcgMyJAJHCLjRjnZquwexGo9vwCT7+gR22Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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