SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5855050e578983a468ad3e62c32596ef53003169a036b03e33092caff79d8203' 
  AND token = 'WEFg3fA+AiyL+AhxvG+qzbHzq9t8ywwHbHUGgJRx9Zk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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