SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d454a2bfe7825fb4cc6baa10ccbab8e4978b4a9d66f2f4ea20bc6db21ef2dee' 
  AND token = 'DvjqtLqzNpalmJndDinDzPsSkDtnR2a3XbWQl8HyZZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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