SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb99b5ea1783d39242335510b82616effaa48985a2874323730a33c69b855a83' 
  AND token = '7/CB8b1jK4u5psM3A3Z6qus/TF7qIg8ZkJYqLegFXds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}