SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '128b6de037ed2d5ccdb52e078b2940c4ced3396979931aa27f551e434d9ebe69' 
  AND token = 'k7ePKZoevb/zVp/tqjuxurrZVyZBQa7YlTp0GB/qCt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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