SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8658bc3044aa765b7af7d0c721508dc73e11dcfe28b29c51f2fc4512739d5fb' 
  AND token = 'UvVazfgLcI5Ml8xu4KYgB3tTEZ32KT0z6mAqbbF3Oxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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