SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17d7c81edb413776b8e52fe63d19aeae0cb5004d974bff12267c3c23b36631b7' 
  AND token = '4AVFjWEeTIg6qz7X9sywyhcNLQzTVPxd/0Pl8mDNVPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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