SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf2cb5ffc7e70d605e1338b5367f9f884adc08c946c56095e4ebd47f059e8e21' 
  AND token = 'g+wu8N/yehV3htWaLzXykBzczV7H+16+YXh9LqMnE/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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