SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb806724e2768e00734079d46ed37d44a74ded2603ec0b7a29d2ead12ac6a457' 
  AND token = 'nJl6M0v7iYRIJj6pIkS04WwizWr+OxnIuAoT0Wl4yBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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