SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee1fff574aa648cdc99e4dae4d473f2edf735c29e8e4b7c31ba2779f9152ed99' 
  AND token = 'UzP+qsiLrwU8VyAcTquEU0pym3w5CkQk/SajrzZa29Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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