SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f0d054f5de25a0f7e6da0bd8448db7e15e384121e5e9d04ca860979fcfb7b36' 
  AND token = '2Z+sh9K2NBXhsl9kCLI73bQwsaYywnxjC2T3qKekvtg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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