SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db89b3805bd73026513c193a0535f5adc90edb91e0937271a91482980b8f1ff9' 
  AND token = 'BtA6SXoSQOSczK70HeFXhGQc9Ade4qemIE5UyPkrXJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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