SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20f11759e05e11cbe10439f24a6151a82cc3060c4496602ac2142324eb08bdd0' 
  AND token = '8+WQrZmfQh9azsGCMIbd5nT8K3G08lGDFbQSy1IbE80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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