SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a3864ae1645bcb6665654d9fc41daa3bf76143239d930e42bc74beef61a5eb0' 
  AND token = 'zoCtnEdHqyz8sqnNIEJRrZQDidb8f72TxBuhcFuWOIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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