SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92c4af4517f72f2339eca968b7dc88cb9cc98f0f0f5898e39c78d7bf0f2229c7' 
  AND token = 'eae8hdsqZT6hCeiLJDXa+mgbOkeGoMnZxXrebXeANZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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