SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29f6dee77a83b660ade7ed865aafb55c8c24cb3884da6fde9498fbe87dc8d868' 
  AND token = 'BC/GmzVmxCwjKBsulYEj8kY5uzQ+1+nuL0ITUSosN0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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