SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd74e8c023ec54b218015a92237be7859c13eb4ff538e4ca94d949fcf492ee3e' 
  AND token = 'hxeWxrR03SCoWuggG5ufBSEJGk9LRo+C9uRQjrZGek8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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