SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f26a3a1be2856abba5ff94189736c1aaad5deb8bbd0e3b70a8202d5a5e9ff41' 
  AND token = 'G3+23PJO2hVYpzDHMm8BDhuTXhcBPmLe5mI+zwlawbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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