SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1dd450a9461997023aad5b189c139e4b55a6681f29d6eb6dc6203af189478823' 
  AND token = 'ifXiCSVT2KzVtICP0LXhBtTb2nzvPu7pgxUjhcEoLD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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