SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebaff83174a1bd6c8857c7b71db1bd7948a6082a5e56988c31a48310ddf8cb8e' 
  AND token = 'kDOfqkPkTfCRWtMoKpO8cBInYhMIOvGOK1gPOQq6XMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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