SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c087892414e753eaf3573daff9d6600a4f7e319f1e93245cc339e207892625f' 
  AND token = 'M+2/3F+g+KgzOYV3dm4SXX/Kv/YfJ6v7W9NDLMCXk0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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