SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbb95c6f479216da0c8d5169181f6122bf81a334832a030ded3d353d2137166b' 
  AND token = 'WxVOtKr9zVoXZ6dyI5OMSQbOXEhYxJ7UVvvDdxHmrHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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