SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26aca923b1d35a6011afde7db1081e19411f263e496c651b0c7f2e938726b404' 
  AND token = 'aGOwhISzz+wFgQo+dcsJ2BkqAZK1yiFKov5WNNVk5Cw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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