SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04f373460966996aa669ce576c50845b9485ab605fd81f80809cd5a6cc51ac4a' 
  AND token = '+D8YvD12Wz0JGun1h2jD9ExNdTpC//GbVd2HWBsJyLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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