SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61bfbea85c43cc4c69323d20b8754186b6733d5580ab09a4a87e3afe107de693' 
  AND token = 'QJrkAPmos/ubFCU9ruBX1MWGMesWq4OyGPlmKgahOQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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