SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da6c698203cf07964eace7fea9741b273faf9473def973d932530ea98ae6b9cf' 
  AND token = 'f3ghtJppzYxTeOxmzW0JqiV14x0TsKfAOvdCbsyWvqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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