SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9617417727ed7c9cd7f93f08facb9aaa8eea8cd3cc7ee1809baf796343a9183f' 
  AND token = 'wsMUkmjBJOIgrsv55Sg8/UuiQ4wDIOzbxZgacWmNaTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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