SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '664969bbca561df3fb0a57d90b5018a4521dd1d9b00fa7f917bf2bcb836fe95a' 
  AND token = 'fQjjeCuCMwk8hZJrD1zYfmnJPxlJH+ohXOwwyqwRtM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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