SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8b959c840c9deea952d469a3f52a5399f1f682dc4ccd558544ef4d4e0c05c63' 
  AND token = 'YfqVavYX1I67wdZ6x40TlTE/2D5gdg321lNyaalPcGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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