SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2357629bd0cbebf5052c38ba8bb334e9575187c8e57552f6fa3b79d9769f1b70' 
  AND token = 'ZMw835Vb3ElegNUiI0dPqyyn8mpAva4cYxMR5gRzsXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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