SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e3b16c29be65efe9d5c3be56e5561966d7e57fd4425a22f540f036d5de58df4' 
  AND token = 'FfIr/mfsvovjBihdQr8ScMSEanubRQ0DQ2ydSndwxSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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