Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b0f257a85dcb823696720dd39c738621340f108fd7ccb79b57cfcdce8e8bbb7' 
  AND token = 'fl4IzgpVYM5YGes11ZsXp6tGZ6yefR2EzQtCvlfTXDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}