SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f096246e02dc68998100476fd2211c17fc6c025cf19b77d8a1bcf9d6091d679' 
  AND token = 'jXKXaUwQXZmmtUOoiRtmRjEQAruRmAetMCmgfe7JyRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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