SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d0a9bd48c8e5104390f28b537194615995b13a74ca09bd17e00f5950e6f352c' 
  AND token = 'azkGsVDwRb7jcAXMIvN+E6tqDwoywO/CpkluQ2h3yaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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