SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cd14728ef518b3cd36ee02415f481f0eea8a894b664205b664db9b573e46e7f' 
  AND token = 'adERUqSnsK13Ngbn9oWpkVxl8jdLMx936JABHYsmc48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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