SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24a9b39c59bd957f2316a79173102ebe43fbb97c592850ab7163767e4b8ef66e' 
  AND token = 'dzudFuKGx8Kc35Nh6Dpa8HKwebWHBq4aDbHtsms3X/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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