SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc31d3ccc13dfa82ae472f57069401e540eec39815bb3728d5aafd878b9c5fe9' 
  AND token = 'bjlpf7mAGagZPGBBNpfse74xzLkhYLyzC0W9kiYrUOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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