SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82522a5930262aa9454c70918ab49399e2539666d99c0a1e82e48fd017573b35' 
  AND token = 'MxmV90af4BtIlV6tSp6AmEfnpKwzWQf1BeXGvKuIFp0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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