SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53b056fc6c2cb4b3c724f857806dfaf1442c992f5f9398db6276e5c92178af8d' 
  AND token = 'a0XWiY+tY5BXmqD0itQMKAq3Z2Qnvcjh4RvFKTZD6eU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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