SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c29c816e19db83a1ea064feb3e42a460c47d2dbe26f9e4863881a3016c30053' 
  AND token = 'BRkzktDWFkKZp6xvVxpfgqFJznudY1O4RBDTEtoRKxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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