SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '087ad15e4eddd39b22786a7bca29133e291f7bae9b0cef34a6cf1e3f9825b952' 
  AND token = 'CctyaXDwV+UksIxQkJCSPVcACoLuUUvHnkhU9Ze+uTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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