SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4397849ab8b07cef6eab74e8666586dab0a8b22759726ab27bb2597995e76ee4' 
  AND token = 'V8QHA5S7EXZ7q8Jl5ibctlg6jnu+1hojvYqvg/XSL+c=' 
  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"
    }
  }
}